U.S. patent application number 14/532262 was filed with the patent office on 2015-02-26 for an infectious cdna clone of north american porcine reproductive and respiratory syndrome (prrs) virus and uses thereof.
The applicant listed for this patent is Zoetis LLC. Invention is credited to Jay Gregory CALVERT, Dal-Young KIM, Raymond R. R. ROWLAND, Michael G. SHEPPARD, Siao Kun W. WELCH.
Application Number | 20150056236 14/532262 |
Document ID | / |
Family ID | 46326385 |
Filed Date | 2015-02-26 |
United States Patent
Application |
20150056236 |
Kind Code |
A1 |
CALVERT; Jay Gregory ; et
al. |
February 26, 2015 |
AN INFECTIOUS cDNA CLONE OF NORTH AMERICAN PORCINE REPRODUCTIVE AND
RESPIRATORY SYNDROME (PRRS) VIRUS AND USES THEREOF
Abstract
The invention provides isolated polynucleotide molecules that
comprise a DNA sequence encoding an infectious RNA sequence
encoding a genetically-modified North American PRRS virus, wherein
the polynucleotide molecule lacks at least one detectable antigenic
epitope of North American PRRS virus. The invention also provides
vaccines comprising genetically modified North American PRRS virus,
RNA molecules, plasmids and viral vectors comprising the isolated
polynucleotide molecules. Also provided are isolated polynucleotide
molecules further comprising at least one nucleotide sequence that
encodes a detectable heterologous antigenic epitope, and vaccines
comprising North American PRRS virus, RNA molecules, plasmids and
viral vectors comprising such isolated polynucleotide
molecules.
Inventors: |
CALVERT; Jay Gregory;
(Otsego, MI) ; SHEPPARD; Michael G.; (Victoria,
AU) ; WELCH; Siao Kun W.; (Kalamazoo, MI) ;
ROWLAND; Raymond R. R.; (Manhattan, KS) ; KIM;
Dal-Young; (Birmingham, AL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Zoetis LLC |
Florham Park |
NJ |
US |
|
|
Family ID: |
46326385 |
Appl. No.: |
14/532262 |
Filed: |
November 4, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12608305 |
Oct 29, 2009 |
8895025 |
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14532262 |
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11586328 |
Oct 25, 2006 |
7618797 |
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12608305 |
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11366851 |
Mar 1, 2006 |
7691389 |
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11586328 |
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10241332 |
Sep 11, 2002 |
7132106 |
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11366851 |
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09470661 |
Dec 22, 1999 |
6500662 |
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10241332 |
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60113345 |
Dec 22, 1998 |
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Current U.S.
Class: |
424/186.1 ;
530/350; 536/23.1 |
Current CPC
Class: |
A61K 2039/55577
20130101; C12N 7/00 20130101; C12N 2770/10034 20130101; A61K
2039/55566 20130101; C12N 2770/10021 20130101; C12N 2770/10022
20130101; C12N 2770/10061 20130101; C07K 2319/60 20130101; G01N
2333/08 20130101; A61K 2039/525 20130101; C07K 2319/42 20130101;
G01N 33/56983 20130101; A61K 2039/5254 20130101; A61K 2039/55544
20130101; A61K 2039/552 20130101; C12N 2770/10043 20130101; A61K
39/00 20130101; C12N 15/86 20130101; A61K 2039/53 20130101; C07K
14/005 20130101 |
Class at
Publication: |
424/186.1 ;
536/23.1; 530/350 |
International
Class: |
C07K 14/005 20060101
C07K014/005; G01N 33/569 20060101 G01N033/569; C12N 7/00 20060101
C12N007/00 |
Claims
1. An isolated polynucleotide molecule comprising a DNA sequence
encoding an infectious RNA molecule encoding a North American PRRS
virus that is genetically modified such that when it infects a
porcine animal it is unable to produce PRRS in the animal yet able
to elicit an effective immunoprotective response against a PRRS
virus in the porcine animal, wherein said DNA sequence is SEQ ID
NO:1 or a sequence homologous thereto, except that it lacks at
least one DNA sequence encoding a detectable antigenic epitope of
North American PRRS virus.
2. The isolated polynucleotide molecule of claim 1, wherein said
molecule lacks at least one DNA sequence encoding a detectable
antigenic epitope of North American PRRS virus in ORF 1a or ORF 1b
within said DNA sequence.
3. The isolated polynucleotide molecule of claim 1, wherein said
molecule lacks at least one DNA sequence encoding a detectable
antigenic epitope of North American PRRS virus in the nonstructural
protein 2 coding region of ORF1a within said DNA sequence.
4. The isolated polynucleotide molecule of claim 1, wherein said
molecule lacks at least one DNA sequence encoding a detectable
antigenic epitope of North American PRRS virus in the hypervariable
region in the nonstructural protein 2 coding region of ORF1a within
said DNA sequence.
5. The isolated polynucleotide molecule of claim 1, wherein said
molecule lacks at least one DNA sequence encoding a detectable
antigenic epitope of North American PRRS virus between amino acids
from 616 to 752 in the hypervariable region in the nonstructural
protein 2 coding region of ORF1a within said DNA sequence.
6. The isolated polynucleotide molecule of claim 1, wherein said
molecule lacks the DNA sequence encoding amino acids 628 and 759 in
the hypervariable region in the nonstructural protein 2 coding
region of ORF1a within said DNA sequence.
7. A vaccine for protecting a porcine animal from infection by a
PRRS virus, wherein said vaccine comprises: a) A genetically
modified North American PRRS virus encoded by an infectious RNA
molecule encoded by the isolated polynucleotide molecule according
to claim 1; b) An infectious RNA molecule encoded by the isolated
polynucleotide molecule according to claim 1; c) The isolated
polynucleotide molecule according to claim 1 in the form of a
plasmid, or d) A viral vector comprising the isolated
polynucleotide molecule according to claim 1; and a carrier
acceptable for veterinary use.
8. The isolated polynucleotide molecule of claim 1, wherein said
isolated polynucleotide molecule further comprises at least one
nucleotide sequence that encodes a detectable heterologous
antigenic epitope.
9. The isolated polynucleotide molecule of claim 8, wherein
translation of the encoded infectious RNA molecule results in
formation of at least one protein consisting of a fusion between a
PRRS virus protein and said heterologous antigenic epitope.
10. The isolated polynucleotide molecule of claim 8, wherein said
nucleotide sequence that encodes a heterologous antigenic epitope
is inserted in ORF 1a or ORF 1b within said DNA sequence.
11. The isolated polynucleotide molecule of claim 8, wherein said
nucleotide sequence that encodes a heterologous antigenic epitope
is inserted in the nonstructural protein 2 coding region of ORF1a
within said DNA sequence.
12. The isolated polynucleotide molecule of claim 8, wherein said
nucleotide sequence that encodes a heterologous antigenic epitope
is inserted in the hypervariable region in the nonstructural
protein 2 coding region of ORF1a within said DNA sequence.
13. The isolated polynucleotide molecule of claim 8, wherein said
nucleotide sequence that encodes a heterologous antigenic epitope
is inserted between amino acids from 628 to 759 in the
hypervariable region in the nonstructural protein 2 coding region
of ORF1a within said DNA sequence.
14. The isolated polynucleotide molecule of claim 8, wherein said
nucleotide sequence that encodes a heterologous antigenic epitope
is inserted between amino acids from 616 to 752 in the
hypervariable region in the nonstructural protein 2 coding region
of ORF1a within said DNA sequence.
15. A vaccine for protecting a porcine animal from infection by a
PRRS virus, wherein said vaccine comprises: a) A genetically
modified North American PRRS virus encoded by an infectious RNA
molecule encoded by the isolated polynucleotide molecule according
to claim 8; b) An infectious RNA molecule encoded by the isolated
polynucleotide molecule according to claim 8; c) The isolated
polynucleotide molecule according to claim 8 in the form of a
plasmid, or d) A viral vector comprising the isolated
polynucleotide molecule according to claim 8; and a carrier
acceptable for veterinary use.
16. A diagnostic kit comprising reagents which are useful for
differentiating between porcine animals naturally infected with a
field strain of a PRRS virus and porcine animals vaccinated with
the vaccine of claim 15.
17. The diagnostic kit of claim 15 having as one of its components
a peptide comprising the amino acid sequences selected from SEQ ID
NO. 64 to 115.
18. The diagnostic kit of claim 16, wherein one of its components
is a peptide comprising the amino acid sequence of SEQ ID NO. 64,
or a peptide fragment thereof 10 amino acid residues in length or
longer.
19. The diagnostic kit of claim 17, wherein said peptide is
optionally a fusion protein.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S.
patent application Ser. No. 11/366,851, filed on Mar. 1, 2006,
which is a continuation-in-part of U.S. patent application Ser. No.
10/241,332, filed Sep. 11, 2002, which is a continuation-in-part of
U.S. patent application Ser. No. 10/127,391, filed on Apr. 22,
2002, which is a continuation of U.S. patent application Ser. No.
09/470,661, filed Dec. 22, 1999, U.S. Pat. No. 6,500,662, which
claims the benefit of priority of U.S. Provisional Application Ser.
No. 60/113,345, filed Dec. 22, 1998, the disclosures of which are
incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention is in the field of animal health and
is directed to infectious cDNA clones of positive polarity RNA
viruses and the construction of vaccines, in particular, swine
vaccines, using such cDNA clones.
BACKGROUND OF THE INVENTION
[0003] Porcine reproductive and respiratory syndrome (PRRS) is a
new disease of swine, first described in 1987 in North America and
in 1990 in Europe. The disease has since spread to Asia and affects
most of the major swine producing countries of the world. Primary
symptoms are reproductive problems in sows and gifts, including
late term abortions, stillbirths and mummies, and litters of small
weak pigs which are born viremic and often fail to survive. In
addition, the syndrome manifests itself as a respiratory disease in
young pigs which spreads horizontally and causes fever, lethargy,
labored breathing, loss of appetite, slow growth, and occasionally
death, often in association with other respiratory pathogens. The
disease furthermore can be transmitted to sows and gilts via the
semen of infected boars, either naturally or by artificial
insemination. For these, and other reasons, PRRS has proven to be a
difficult disease to control and therefore one of the most
economically damaging diseases to the swine industry.
[0004] The causative agent of PRRS is the PRRS virus, which exists
as two genetically and serologically distinct types (Murtaugh, M.
P. et al, 1995, Arch-Virol. 140, 1451-1460; Suarez, P. et al.,
1996, Virus Research 42:159-165). The two types are believed to
have first entered swine populations independently, one in North
America and the other in Europe, in the 1980's, from unknown
biological reservoirs, possibly of rodent or avian origin. The
European type, represented by the prototype "Lelystad Virus", was
isolated and sequenced in the Netherlands in 1991 (Terpstra, C. et
al., 1991, Vet. Quart. 13:131-136; Wensvoort, G. et al., 1991, Vet.
Quart. 13:121-130; Wensvoort, G. et al., WO 92/213751992
(PCT/NL92/00096), 1992; Meulenberg, J. J. M. et al., 1993, Virol.
192:62-72).
[0005] Both the North American PRRS virus and the European PRRS
virus are classified within the family Arteriviridae, which also
includes equine arteritis virus, lactate dehydrogenase-elevating
virus, and simian haemorrhagic fever virus. The arteriviruses are
in turn placed within the order Nidovirales, which also includes
the coronaviruses and toroviruses. The nidoviruses are enveloped
viruses having genomes consisting of a single strand of positive
polarity RNA. The genomic RNA of a positive-stranded RNA virus
fulfills the dual role in both storage and expression of genetic
information. No DNA is involved in replication or transcription in
nidoviruses. The reproduction of nidoviral genomic RNA is thus a
combined process of genome replication and mRNA transcription.
Moreover, some proteins are translated directly from the genomic
RNA of nidoviruses. The molecular biology of the family
Arteriviridae has recently been reviewed by Snijder and Meulenberg
(Snijder, E. J. and Meulenberg, J. J. M., 1998, Journal of General
Virology 79:961-979).
[0006] Currently available commercial vaccines against PRRS are
either conventional modified live virus (cell culture, attenuated)
or conventional killed (inactivated cell culture preparations of
virulent virus). Several of these vaccines have been criticized
based on safety and/or efficacy concerns. The development of a
second generation of PRRS vaccines, based upon specific additions,
deletions, and other modifications to the PRRS genome, is therefore
highly desirable. However, since the PRRS viruses do not include
any DNA intermediates during their replication, such vaccines have
thus far awaited the construction of full-length cDNA clones of
PRRS viruses for manipulation by molecular biology techniques at
the DNA level. Very recently, a full-length infectious cDNA clone
of the European PRRS virus has been reported (Meulenberg, J. J. M.
et al., 1998, supra; Meulenberg, J. J. M. et al, 1988, J. Virol.
72, 380-387.).
[0007] The preceding publications, as well as all other references
discussed below in this application, are hereby incorporated by
reference in their entireties.
SUMMARY OF THE INVENTION
[0008] The subject invention provides an isolated polynucleotide
molecule comprising a DNA sequence encoding an infectious RNA
molecule encoding a North American PRRS virus that is genetically
modified such that when it infects a porcine animal it is unable to
produce PRRS in the animal yet able to elicit an effective
immunoprotective response against a PRRS virus in the porcine
animal, wherein said DNA sequence is SEQ ID NO:1 or a sequence
homologous thereto, except that it lacks at least one DNA sequence
encoding a detectable antigenic epitope of North American PRRS
virus.
[0009] The subject invention further provides an isolated
polynucleotide molecule where at least one DNA sequence encoding a
detectable antigenic epitope of North American PRRS virus in ORF 1a
or ORF 1b within said DNA sequence is deleted.
[0010] The subject invention further provides an isolated
polynucleotide molecule where at least one DNA sequence encoding a
detectable antigenic epitope of North American PRRS virus in the
nonstructural protein 2 coding region of ORF1a within said DNA
sequence is deleted.
[0011] The subject invention further provides an isolated
polynucleotide molecule where at least one DNA sequence encoding a
detectable antigenic epitope of North American PRRS virus in the
hypervariable region in the nonstructural protein 2 coding region
of ORF1a within said DNA sequence is deleted.
[0012] The subject invention further provides an isolated
polynucleotide molecule where the DNA sequence encoding amino acids
628 and 759 in the hypervariable region in the nonstructural
protein 2 coding region of ORF1a within said DNA sequence is
deleted.
[0013] The subject invention further provides a vaccine for
protecting a porcine animal from infection by a PRRS virus, wherein
said vaccine comprises a genetically modified North American PRRS
virus encoded by an infectious RNA molecule encoded by the isolated
polynucleotide molecule as described above; an infectious RNA
molecule encoded by the isolated polynucleotide molecule as
described above; an isolated polynucleotide molecule as described
above in the form of a plasmid, or a viral vector comprising the
isolated polynucleotide molecule as described above, and a carrier
acceptable for veterinary use.
[0014] The subject invention also provides an isolated
polynucleotide molecule comprising a DNA sequence encoding an
infectious RNA molecule encoding a North American PRRS virus that
is genetically modified such that when it infects a porcine animal
it is unable to produce PRRS in the animal yet able to elicit an
effective immunoprotective response against a PRRS virus in the
porcine animal, wherein the DNA sequence is SEQ ID NO:1 or a
sequence homologous thereto, except that it lacks at least one DNA
sequence encoding a detectable antigenic epitope of North American
PRRS virus, wherein it further comprises at least one nucleotide
sequence that encodes a detectable heterologous antigenic
epitope.
[0015] The present invention further provides an isolated
polynucleotide molecule comprising at least one nucleotide sequence
encoding a heterologous antigenic epitope, wherein said nucleotide
sequence encoding a heterologous antigenic epitope is inserted in
ORF 1a or ORF 1b within said DNA sequence encoding an infectious
RNA molecule encoding a North American PRRS virus.
[0016] The present invention further provides an isolated
polynucleotide molecule comprising at least one nucleotide sequence
encoding a heterologous antigenic epitope, wherein said nucleotide
sequence encoding a heterologous antigenic epitope is inserted in
the nonstructural protein 2 coding region of ORF 1a within said DNA
sequence encoding an infectious RNA molecule encoding a North
American PRRS virus.
[0017] The present invention further provides an isolated
polynucleotide molecule comprising at least one nucleotide sequence
encoding a heterologous antigenic epitope, wherein said nucleotide
sequence encoding a heterologous antigenic epitope is inserted in
the hypervariable region in the nonstructural protein 2 coding
region of ORF 1a within said DNA sequence encoding an infectious
RNA molecule encoding a North American PRRS virus.
[0018] The present invention further provides an isolated
polynucleotide molecule comprising at least one nucleotide sequence
encoding a heterologous antigenic epitope, wherein said nucleotide
sequence encoding a heterologous antigenic epitope is inserted in
the hypervariable region in the nonstructural protein 2 coding
region of ORF 1a between the DNA sequence encoding amino acids 628
and 759 in the hypervariable region in the nonstructural protein 2
coding region of ORF1a within said DNA sequence.
[0019] The present invention further provides a vaccine for
protecting a porcine animal from infection by a PRRS virus, wherein
said vaccine comprises a genetically modified North American PRRS
virus encoded by an infectious RNA molecule encoded by an isolated
polynucleotide molecule as described above, an infectious RNA
molecule encoded by an isolated polynucleotide molecule as
described above, an isolated polynucleotide molecule as described
above, or a viral vector comprising an isolated polynucleotide
molecule as described above, and a carrier acceptable for
veterinary use.
[0020] The present invention also provides a diagnostic kit for
differentiating between porcine animals vaccinated with the above
described vaccines and porcine animals infected with field strains
of PRRS virus. Said kit contains as one of its components at least
one peptide having a sequence comprising the 132 amino acid region
deleted within the PRRS virus strains presently described.
Alternative, the kit can have as one of its components the
corresponding peptide from any PRRS virus strain. The kit can
otherwise have as one of its components a smaller peptide
corresponding to a portion of the 132 amino acid sequence
comprising the nsp2 deletion, from 10 amino acid residues or upward
in length. The peptide can additionally be in the form of a fusion
protein.
BRIEF DESCRIPTION OF THE FIGURES
[0021] FIG. 1: Cloning strategy for construction of full-length
infectious cDNA clone of North American PRRS virus, pT7P129A.
Arrowheads represent T7 promoter sequences.
[0022] FIG. 2: Serum viremia following infection with P129A or
recombinant PRRS virus rP129A-1. Determined by plaque assay on
MARC-145 cells. The lower limit of detection is 5 pfu/ml (or 0.7 on
the log scale).
[0023] FIG. 3: Anti-PRRS virus serum antibody following infection
with P129A or recombinant PRRS virus rP129A-1. Determined by
HerdChek PRRS ELISA assay (IDEXX (Westbrook, Me., USA)).
[0024] FIG. 4: Genome organization of PRRSV virus. Location or
range of various deletions and insertion sites, including: ORF 1a
and 1b, Nsp2, the hypervariable region of Nsp2, the deleted region
within Nsp2 encoding amino acids 628-759, and the MluI and SgrA1
sites at genome positions 3219 and 3614, between which GFP or the 9
amino acid HA tag were inserted. The active site residues of the
cysteine protease domain (Cys437 and His507) and the hypervariable
region are indicated. The hypervariable region of nsp2 corresponds
approximately to genome coordinates 2720-3980 in P129.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Production and manipulation of the isolated polynucleotide
molecules described herein are within the skill in the art and can
be carried out according to recombinant techniques described, among
other places, in Maniatis, et al., 1989, Molecular Cloning, A
Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring
Harbor, N.Y.; Ausubel, et al., 1989, Current Protocols In Molecular
Biology, Greene Publishing Associates & Wiley Interscience, NY;
Sambrook, at al., 1989, Molecular Cloning: A Laboratory Manual, 2d
ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.;
Innis at alt (eds), 1995, PCR Strategies, Academic Press, Inc., San
Diego; and Erlich (ed), 1992, PCR Technology, Oxford University
Press, New York, all of which are incorporated herein by
reference.
[0026] A. Isolated Polynucleotide Molecules and RNA Molecules
Encoding Genetically Modified North American PRRS Viruses.
[0027] The present invention provides isolated polynucleotide
molecules comprising DNA sequences that encode infectious RNA
molecules that encode genetically modified North American PRRS
viruses.
[0028] The subject invention provides an isolated polynucleotide
molecule comprising a DNA sequence encoding an infectious RNA
molecule that encodes a North American PRRS virus, wherein said DNA
sequence is SEQ ID NO:1 or a sequence homologous thereto. The
present invention provides an isolated polynucleotide molecule
comprising a DNA sequence encoding an infectious RNA molecule that
encodes a North American PRRS virus, wherein said DNA sequence is
the sequence beginning with and including nucleotide 1 through and
including nucleotide 15,416 of SEQ ID NO:1, except that the
nucleotide corresponding to nucleotide 12,622 of SEQ ID NO:1 is a
guanine instead of an adenine and the nucleotide corresponding to
nucleotide 1,559 of SEQ ID NO:1 is a thymine instead of a cytosine.
Said DNA sequence encodes an infectious RNA molecule that is the
RNA genome of the North American PRRS isolate P129.
[0029] It is understood that terms herein referring to nucleic acid
molecules such as "isolated polynucleotide molecule", "nucleotide
sequence", "open reading frame (ORF)", and the like, unless
otherwise specified, include both DNA and RNA molecules and include
both single-stranded and double-stranded molecules. Also, when
reference to a particular sequence from the "Sequence Listing"
section of the subject application is made, it is intended, unless
otherwise specified, to refer to both the DNA of the "Sequence
Listing", as well as RNA corresponding to the DNA sequence, and
includes sequences complementary to the DNA and RNA sequences. In
such contexts in this application, "corresponding to" refers to
sequences of DNA and RNA that are identical to one another but for
the fact that the RNA sequence contains uracil in place of thymine
and the backbone of the RNA molecule contains ribose instead of
deoxyribose.
[0030] For example, SEQ ID NO:1 is a DNA sequence corresponding to
the RNA genome of a North American PRRS virus. Thus, a DNA sequence
complementary to the DNA sequence set forth in SEQ ID NO:1 is a
template for, i.e. is complementary to or "encodes", the RNA genome
of the North American PRRS virus (i.e., RNA that encodes the North
American PRRS virus). Nonetheless, a reference herein to SEQ ID
NO:1 includes both the RNA sequence corresponding to SEQ ID NO:1
and a DNA sequence complementary to SEQ ID NO:1.
[0031] Furthermore, when reference is made herein to sequences
homologous to a sequence in the Sequence Listing, it is to be
understood that sequences homologous to a sequence corresponding to
the sequence in the Sequence Listing and sequences homologous to a
sequence complementary to the sequence in the Sequence Listing are
also included.
[0032] An "infectious RNA molecule", for purposes of the present
invention, is an RNA molecule that encodes the necessary elements
for viral replication, transcription, and translation into a
functional virion in a suitable host cell, provided, if necessary,
with a peptide or peptides that compensate for any genetic
modifications, e.g. sequence deletions, in the RNA molecule.
[0033] An "isolated infectious RNA molecule" refers to a
composition of matter comprising the aforementioned infectious RNA
molecule purified to any detectable degree from its naturally
occurring state, if such RNA molecule does indeed occur in nature.
Likewise, an "isolated polynucleotide molecule" refers to a
composition of matter comprising a polynucleotide molecule of the
present invention purified to any detectable degree from its
naturally occurring state, if any.
[0034] For purposes of the present invention, the nucleotide
sequence of a second polynucleotide molecule (either RNA or DNA) is
"homologous" to the nucleotide sequence of a first polynucleotide
molecule where the nucleotide sequence of the second polynucleotide
molecule encodes the same polyaminoacid as the nucleotide sequence
of the first polynucleotide molecule as based on the degeneracy of
the genetic code, or when it encodes a polyaminoacid that is
sufficiently similar to the polyaminoacid encoded by the nucleotide
sequence of the first polynucleotide molecule so as to be useful in
practicing the present invention. For purposes of the present
invention, a polynucleotide molecule is useful in practicing the
present invention where it can be used as a diagnostic probe to
detect the presence of the North American PRRS virus in a fluid or
tissue sample of an infected pig, e.g. by standard hybridization or
amplification techniques. It is to be understood that the
polyaminoacid encoded by the nucleotide sequence of the
polynucleotide molecule can comprise a group of two or more
polyaminoacids. Generally, the nucleotide sequence of a second
polynucleotide molecule is homologous to the nucleotide sequence of
a first polynucleotide molecule if it has at least about 70%
nucleotide sequence identity to the nucleotide sequence of the
first polynucleotide molecule as based on the BLASTN algorithm
(National Center for Biotechnology Information, otherwise known as
NCBI, (Bethesda, Md., USA) of the United States National Institute
of Health). Preferably, a homologous nucleotide sequence has at
least about 75% nucleotide sequence identity, even more preferably
at least about 85% nucleotide sequence identity. Since the genetic
code is degenerate, a homologous nucleotide sequence can include
any number of "silent" base changes, i.e. nucleotide substitutions
that nonetheless encode the same amino acid. A homologous
nucleotide sequence can further contain non-silent mutations, i.e.
base substitutions, deletions, or additions resulting in amino acid
differences in the encoded polyaminoacid, so long as the sequence
remains at least about 70% identical to the polyaminoacid encoded
by the first nucleotide sequence or otherwise is useful for
practicing the present invention. Homologous nucleotide sequences
can be determined by comparison of nucleotide sequences, for
example by using BLASTN, above. Alternatively, homologous
nucleotide sequences can be determined by hybridization under
selected conditions. For example, the nucleotide sequence of a
second polynucleotide molecule is homologous to SEQ ID NO:1 if it
hybridizes to the complement of SEQ ID NO:1 under moderately
stringent conditions, e.g., hybridization to filter-bound DNA in
0.5 M NaHPO.sub.4, 7% sodium dodecyl sulfate (SDS), 1 mM EDTA at
65.degree. C., and washing in 0.2.times.SSC/0.1% SDS at 42.degree.
C. (see Ausubel et al. above), or conditions which will otherwise
result in hybridization of sequences that encode a North American
PRRS virus as defined below. In another embodiment, a second
nucleotide sequence is homologous to SEQ ID NO:1 if it hybridizes
to the complement of SEQ ID NO:1 under highly stringent conditions,
e.g. hybridization to filter-bound DNA in 0.5 M NaHPO.sub.4, 7%
SDS, 1 mM EDTA at 65.degree. C., and washing in 0.1.times.SSC/0.1%
SDS at 68.degree. C. (Ausubel et al., above).
[0035] It is furthermore to be understood that the isolated
polynucleotide molecules and the isolated RNA molecules of the
present invention include both synthetic molecules and molecules
obtained through recombinant techniques, such as by in vitro
cloning and transcription.
[0036] As used herein, the term "PRRS" encompasses disease symptoms
in swine caused by a PRRS virus infection. Examples of such
symptoms include, but are not limited to, abortion in pregnant
females, and slow growth, respiratory difficulties, loss of
appetite, and mortality in young pigs. As used herein, a PRRS virus
that is "unable to produce PRRS" refers to a virus that can infect
a pig, but which does not produce any disease symptoms normally
associated with a PRRS infection in the pig, or produces such
symptoms, but to a lesser degree, or produces a fewer number of
such symptoms, or both.
[0037] The terms "porcine" and "swine" are used interchangeably
herein and refer to any animal that is a member of the family
Suidae such as, for example, a pig. "Mammals" include any
warm-blooded vertebrates of the Mammalia class, including
humans.
[0038] The term "PRRS virus", as used herein, unless otherwise
indicated, means any strain of either the North American or
European PRRS viruses.
[0039] The term "field strain" or "field strains", as used herein,
unless otherwise indicated, means any strain of either North
American or European PRRS virus which occurs in nature, and is
infectious to a pig.
[0040] The term "North American PRRS virus" means any PRRS virus
having genetic characteristics associated with a North American
PRRS virus isolate, such as, but not limited to the PRRS virus that
was first isolated in the United States around the early 1990's
(see, e.g., Collins, J. E., et al., 1992, J. Vet. Diagn. Invest,
4:117-126); North American PRRS virus isolate MN-1b (Kwang, J. et
al., 1994, J. Vet. Diagn. Invest. 6:293-296); the Quebec IAF-exp91
strain of PRRS (Mardassi, H. et al., 1995, Arch. Virol.
140:1405-1418); and North American PRRS virus isolate VA 2385
(Meng, X.-J et al., 1994, J. Gen. Virol 75:1795-1801). Genetic
characteristics refers to genomic nucleotide sequence similarity
and amino acid sequence similarity shared by North American PRRS
virus strains. For purposes of the present invention, a North
American PRRS virus is a virus that is encoded by an RNA sequence
the same as or homologous to SEQ ID NO:1, wherein the term
"homologous" is as defined previously. Thus, strains of North
American PRRS viruses have, preferably, at least about 70% genomic
nucleotide sequence identity with SEQ ID NO:1, and more preferably
at least about 75% genomic nucleotide sequence identity with SEQ ID
NO:1, at least about 85% genomic nucleotide sequence identity with
SEQ ID NO:1 being even more preferred.
[0041] The term "European PRRS virus" refers to any strain of PRRS
virus having the genetic characteristics associated with the PRRS
virus that was first isolated in Europe around 1991 (see, e.g.,
Wensvoort, G., et al., 1991, Vet. Q. 13:121-130). "European PRRS
virus" is also sometimes referred to in the art as "Lelystad
virus".
[0042] Unless otherwise indicated, a North American PRRS virus is
"useful in practicing the present invention" if its characteristics
are within the definition of a North American PRRS virus set forth
herein. For example, a virus encoded by one of the isolated
polynucleotide molecules of the present invention is a "North
American PRRS virus useful in practicing the present invention" if
it, e.g., has genetic characteristics associated with a North
American PRRS virus.
[0043] Other polyaminoacids are "useful in practicing the present
invention", e.g., peptides encoded by polynucleotide sequences
homologous to North American PRRS virus ORFs, if they can
compensate for an RNA molecule encoding a genetically modified PRRS
virus, deficient in a gene essential for expressing functional PRRS
virions, in a transfected host cell so that functional PRRS virions
can be generated by the cell.
[0044] The term "open reading frame", or "ORF", as used herein,
means the minimal nucleotide sequence required to encode a
particular PRRS virus protein without an intervening stop
codon.
[0045] Terms such as "suitable host cell" and "appropriate host
cell", unless otherwise indicated, refer to cells into which RNA
molecules (or isolated polynucleotide molecules or viral vectors
comprising DNA sequences encoding such RNA molecules) of the
present invention can be transformed or transfected. "Suitable host
cells" for transfection with such RNA molecules, isolated
polynucleotide molecules, or viral vectors, include mammalian,
particularly porcine, and avian cells, and are described in further
detail below.
[0046] A "functional virion" is a virus particle that is able to
enter a cell capable of hosting a PRRS virus, and express genes of
its particular RNA genome (either an unmodified genome or a
genetically modified genome as described herein) within the cell.
Cells capable of hosting a PRRS virus include porcine alveolar
macrophage cells and MARC 145 monkey kidney cells. Other mammalian
or avian cells, especially other porcine cells, may also serve as
suitable host cells for PRRS virions.
[0047] The isolated polynucleotide molecules of the present
invention encode North American PRRS viruses that can be used to
prepare live, killed, or attenuated vaccines using art-recognized
methods for protecting swine from infection by a PRRS virus, as
described in further detail below. These isolated polynucleotide
molecules are also useful as vectors for delivering heterologous
genes into mammals, including swine, or birds, as is also described
in detail below. Furthermore, these isolated polynucleotide
molecules are useful because they can be mutated using molecular
biology techniques to encode genetically-modified North American
PRRS viruses useful, inter alia, as vaccines for protecting swine
from PRRS infection. Such genetically-modified North American PRRS
viruses, as well as vaccines comprising them, are also described in
further detail below.
[0048] The term "genetically modified", as used herein and unless
otherwise indicated, means genetically mutated, i.e. having one or
more nucleotides replaced, deleted and/or added. Polynucleotide
molecules can be genetically mutated using recombinant techniques
known to those of ordinary skill in the art, including by
site-directed mutagenesis, or by random mutagenesis such as by
exposure to chemical mutagens or to radiation, as known in the art.
In one embodiment, genetic modification of the North American PRRS
virus of the present invention renders the virus unable to
replicate effectively, or reduces its ability to replicate
effectively, in a bird or mammal in which the wild-type virus
otherwise can effectively replicate. In another embodiment, the
genetically modified North American PRRS virus of the present
invention remains able to replicate effectively in birds or mammals
infected therewith. "Effective replication" means the ability to
multiply and produce progeny viruses (virions) in an infected
animal, i.e. the ability to "productively infect" an animal.
[0049] The subject invention further provides an isolated
polynucleotide molecule comprising a DNA sequence encoding an
infectious RNA molecule which encodes a genetically modified North
American PRRS virus that is unable to produce PRRS in a porcine
animal, wherein the DNA sequence encoding the infectious RNA
molecule encoding said North American PRRS virus is SEQ ID NO:1 or
a sequence homologous thereto, except that it contains one or more
mutations that genetically disable the encoded PRRS virus in its
ability to produce PRRS. "Genetically disabled" means that the PRRS
virus is unable to produce PRRS in a swine animal infected
therewith.
[0050] The subject invention also provides an isolated
polynucleotide molecule comprising a DNA sequence encoding an
infectious RNA molecule which encodes a North American PRRS virus
that is genetically modified such that when it infects a porcine
animal it: a) is unable to produce PRRS in the animal, and b) is
able to elicit an effective immunoprotective response against
infection by a PRRS virus in the animal, wherein the DNA sequence
encoding said North American PRRS virus is SEQ ID NO:1 or a
sequence homologous thereto, except that it contains one or more
mutations that genetically disable the encoded PRRS virus in its
ability to produce PRRS.
[0051] The term "immune response" for purposes of this invention
means the production of antibodies and/or cells (such as T
lymphocytes) that are directed against, or assist in the
decomposition or inhibition of, a particular antigenic epitope or
particular antigenic epitopes. The phrases "an effective
immunoprotective response", "immunoprotection", and like terms, for
purposes of the present invention, mean an immune response that is
directed against one or more antigenic epitopes of a pathogen so as
to protect against infection by the pathogen in a vaccinated
animal. For purposes of the present invention, protection against
infection by a pathogen includes not only the absolute prevention
of infection, but also any detectable reduction in the degree or
rate of infection by a pathogen, or any detectable reduction in the
severity of the disease or any symptom or condition resulting from
infection by the pathogen in the vaccinated animal as compared to
an unvaccinated infected animal. An effective immunoprotective
response can be induced in animals that have not previously been
infected with the pathogen and/or are not infected with the
pathogen at the time of vaccination. An effective immunoprotective
response can also be induced in an animal already infected with the
pathogen at the time of vaccination.
[0052] An "antigenic epitope" is, unless otherwise indicated, a
molecule that is able to elicit an immune response in a particular
animal or species. Antigenic epitopes are proteinaceous molecules,
i.e. polyaminoacid sequences, optionally comprising non-protein
groups such as carbohydrate moieties and/or lipid moieties.
[0053] The term "pathogenically infecting" used herein refers to
the ability of a pathogen to infect an animal and cause a disease
in the animal. As an example, a PRRS virus is capable of
pathogenically infecting a porcine animal since it can cause PRRS
in swine. However, although a PRRS virus may be able to infect,
either productively or non-productively, a bird or another mammal,
such as a human, it does not pathogenically infect any animal other
than a porcine animal since it does not cause any disease in
animals other than porcine animals.
[0054] The genetically modified North American PRRS viruses encoded
by the above-described isolated polynucleotide molecules are, in
one embodiment, able to elicit an effective immunoprotective
response against infection by a PRRS virus. Such genetically
modified North American PRRS viruses are preferably able to elicit
an effective immunoprotective response against any strain of PRRS
viruses, including both European and North American strains.
[0055] The present invention provides a mutation or mutations in
the isolated polynucleotide molecule encoding the genetically
disabled North American PRRS virus that are non-silent and occur in
one or more open reading frames of the nucleotide sequence encoding
the North American PRRS virus; i.e., the mutation or mutations
occur in one or more of the sequences within the nucleotide
sequence encoding the North American PRRS virus that are the same
as or homologous to ORFs 1a, 1b, 2, 3, 4, 5, 6, or 7 of SEQ ID
NO:1. The mutation or mutations may occur in one or more noncoding
regions of the North American PRRS virus genome, such as, for
example, in the leader sequence of the North American PRRS virus
genome; i.e., the mutation or mutations occur within the sequence
that is the same as or homologous to the sequence of nucleotides
1-191 of SEQ ID NO:1. In the same isolated polynucleotide molecule,
mutations can occur in both coding and noncoding regions.
[0056] As used herein, unless otherwise indicated, "noncoding
regions" of the nucleotide sequence encoding the North American
PRRS virus refer to those sequences of RNA that are not translated
into a protein and those sequences of cDNA that encode such RNA
sequences. Coding regions refer to those sequences of RNA from
which North American PRRS virus proteins are expressed, and also
refer to cDNA that encodes such RNA sequences. Likewise, "ORFs"
refer both to RNA sequences that encode North American PRRS virus
proteins and to cDNA sequence encoding such RNA sequences.
[0057] Determining suitable locations for a mutation or mutations
that will encode a North American PRRS virus that is genetically
disabled so that it is unable to produce PRRS yet remains able to
elicit an effective immunoprotective response against infection by
a PRRS virus can be made based on the SEQ ID NO:1 provided herein.
One of ordinary skill can refer to the sequence of the infectious
cDNA clone of North American PRRS virus provided by this invention,
make sequence changes which will result in a mutation, and test the
viruses encoded thereby both for their ability to produce PRRS in
swine, and to elicit an effective immunoprotective response against
infection by a PRRS virus. In so doing, one of ordinary skill can
refer to techniques known in the art and also those described
and/or exemplified herein.
[0058] For example, an ORF of the sequence encoding the infectious
RNA molecule encoding the North American PRRS virus can be mutated
and the resulting genetically modified North American PRRS virus
tested for its ability to cause PRRS. The ORF of a North American
PRRS virus encodes proteins as follows: ORF 1a encodes a
polyprotein comprising protease function; ORF 1b encodes a
polyprotein comprising replicase (RNA polymerase) and helicase
functions; ORFs 2, 3, and 4 encode small membrane glycoproteins;
ORF 5 encodes a major envelope glycoprotein; ORF 6 encodes a
nonglycosylated integral membrane protein; and ORF 7 encodes a
nucleocapsid protein. Genetic mutations of one or more of these
ORFs can be used in preparing the genetically modified North
American PRRS viruses described infra.
[0059] The subject invention also provides an isolated
polynucleotide molecule comprising a DNA sequence encoding an
infectious RNA molecule encoding a North American PRRS virus that
is genetically modified such that it lacks at least one DNA
sequence encoding a detectable antigenic epitope of North American
PRRS virus, wherein the DNA sequence encoding the RNA molecule
encoding the North American PRRS virus is SEQ ID NO:1 or a sequence
homologous thereto.
[0060] A "detectable antigenic epitope" is, unless otherwise
indicated, a molecule that is able to elicit an immune response in
a particular animal or species, which immune response is measurable
via an assay or method.
[0061] In a non-limiting embodiment, the detectable antigenic
epitope which is deleted is within ORF 1a or OAF 1b. In another
embodiment, the detectable antigenic epitope which is deleted is
within the sequences encoding for the nonstructural protein 2
(nsp2), which is part of ORF 1a. In a separate embodiment, the
detectable antigenic epitope which is deleted is within the
hypervariable C-terminal portion of nsp2. In a further embodiment,
the detectable antigenic epitope which is deleted, or lacking, is
the DNA sequence encoding any 10 aa polypeptides or longer, up to
400 aa length polypeptides, where the DNA sequence that may be
deleted is the DNA that encodes any amino acids from 616 to 752 of
the hypervariable region of nsp2. This region, from 616 to 752 of
nsp2, is the conserved sub-region within the hypervariable region
of nsp2.
[0062] One example of such a deletion is Example XI. In Example XI
a deletion is described which results in the lack of a DNA sequence
encoding amino acids 628 through 759 of nsp2. This deletion is
within the region encoding the hypervariable C-terminal portion of
nsp2. This Example XI deletion, which lacks the DNA sequence
encoding amino acids from 628 to 759 in the hypervariable region is
considered as being taken from the region of the DNA sequence
encoding amino acids 616 to 752 in the hypervariable region because
the region begins in the region of the DNA sequence encoding amino
acids 616 to 752 in the hypervariable region. The deleted region
can extend beyond the conserved sub-region in either direction, but
the entire deleted region should be no greater than the amount of
DNA that encodes for a polypeptide of about 400 aa. Table 1 shows
the relative positions of some of the nucleotides and amino acids
in relation to certain regions of the genome for SEQ. ID. NO.
1.
TABLE-US-00001 TABLE 1 Genome coordinates of nsp2 regions based on
SEQ ID NO. 1. Genome Amino Amino position acid range acid range
Landmark (nucleotides) (w/in ORF1a) (w/in nsp2) Entire 1-15,450 NA
NA genome (1-15,395 w/o polyA tail) ORF1a 192-7685 1-2497 NA (7491
nt) (2497 aa) ATGTCT...TGCTAG MSGIL...QCLNC Nsp2 1341-4262 384-1357
1-974 (2922 nt) (974 aa) (974 aa) GCTGGA...CTGGGC AGKRA...GRLLG
AGKRA...GRLLG Hypervariable 2721-3980 844-1263 461-880 region of
nsp2 (1260 nt) (420 aa) (420 aa) AGATCT...CTCTTT RSDYG...LFCLF
RSDYG...LFCLF Conserved 3186-3596 999-1135 616-752 subregion w/in
(411 nt) (137 aa) (137 aa) hypervariable region TCATCA...CGCATC
SSSSS...DIPRI SSSSS...DIPRI Deletion in 3222-3617 1011-1142 628-759
Example XI (396 nt) (132 aa) (132 aa) CGCCCA...AATACC RPKYS...KIENT
RPKYS...KIENT
[0063] Such deletions may be anywhere within the hypervariable
region, including the region of the DNA encoding the conserved
sub-region of amino acids from 616 to 752 in nsp2, and such
deletions may extend into the flanking regions as well, provided
the DNA encodes at least 10 amino acids from the conserved
sub-region or from other locations in the hypervariable region.
[0064] In a further embodiment, the detectable antigenic epitope
which is removed is taken from the DNA sequence encoding amino
acids 628 through 759 of nsp2, which is both within the conserved
sub-region and within the region encoding the hypervariable
C-terminal portion of nsp2.
[0065] In a further embodiment, the detectable antigenic epitope
which is deleted is taken from the DNA sequence encoding
polypeptides as short as ten amino acids, or as long as the entire
hypervariable region of nsp2 which can extend up to 400 amino
acids. Specifically the region may be from 10 to 100 aa in length,
from 100 to 150, from 150 to 200, from 200 to 300 or from 300 to
400 amino acids in length. For example, the deleted DNA can encode
the peptide that comprises amino acids 1-10 of the hypervariable
region of the nsp2 peptide. The peptide can be amino acids 2-11 of
the hypervariable region. The peptide can be amino acids 3-12 of
the hypervariable region. Peptides are selected in this fashion by
progressively "walking" down the amino acid sequence of the
hypervariable region of nsp2, all of the way through the
hypervariable region, more particularly through the region of the
DNA encoding the conserved subregion of amino acids from 616 to 752
of nsp2 within the hypervariable region, and it may extend into the
flanking regions. A specific example of this is Example XI where
the deleted region is the DNA sequence encoding amino acids 628
through 759 in the hypervariable region.
[0066] In addition to 10-mer peptides, the deleted fragment can be
a DNA encoding 11 amino acid residues in length, beginning with a
fragment comprising amino acid 1-11 of the hypervariable region,
and progressing to the C-terminal end of the hypervariable region.
Similarly, the fragment can be DNA encoding 12, 13, 14, 15, 16, 17,
18, 19, 20 or more residues in length, up to 400 residues in
length, and such peptides are readily identifiable by beginning at
residue 1 and "walking" down the amino acid sequence of the
corresponding hypervariable region of nsp2. Such a strategy can be
applied to the corresponding hypervariable region of the nsp2
sequence from any strain of PRRS virus.
[0067] The subject invention also provides an isolated
polynucleotide molecule comprising a DNA sequence encoding an
infectious RNA molecule encoding a North American PRRS virus that
is genetically modified such that it lacks at least one DNA
sequence encoding a detectable antigenic epitope of North American
PRRS virus, wherein it further comprises one or more heterologous
antigenic epitopes, wherein the DNA sequence encoding the RNA
molecule encoding the North American PRRS virus is SEQ ID NO:1 or a
sequence homologous thereto, and further comprising one or more
additional nucleotide sequences that each encode a heterologous
antigenic epitope, and wherein each heterologous antigenic epitope
is capable of inducing an effective immunoprotective response
against a particular pathogen in a mammal or a bird.
[0068] A pathogen against which an effective immunoprotective
response can be induced by means of the above recited aspect of the
present invention is any pathogen, such as a virus, bacteria,
fungus, or protozoan, capable of causing a disease in a mammal or
bird, which pathogen comprises or has associated therewith one or
more antigenic epitopes which can be used to induce an effective
immunoprotective response against the pathogen in the mammal or
bird.
[0069] The term "heterologous antigenic epitope" for purposes of
the present invention means an antigenic epitope, as defined above,
not normally found in a wild-type North American PRRS virus. A
nucleotide sequence encoding a heterologous antigenic epitope can
be inserted into a North American PRRS viral genome using known
recombinant techniques. Antigenic epitopes useful as heterologous
antigenic epitopes for the present invention include additional
North American PRRS virus antigenic epitopes, antigenic epitopes
from European PRRS viruses, antigenic epitopes from swine pathogens
other than PRRS viruses, or antigenic epitopes from pathogens that
pathogenically infect birds or mammals other than swine, including
humans. Sequences encoding such antigenic epitopes are known in the
art or are provided herein. For example, a second North American
PRRS virus envelope protein, encoded by North American PRRS ORF 5
described herein, can be inserted into a DNA sequence encoding an
RNA molecule encoding a North American PRRS virus of the present
invention to generate a genetically modified North American PRRS
virus comprising an additional envelope protein as a heterologous
antigenic epitope. Such a genetically modified North American PRRS
virus can be used to induce a more effective immunoprotective
response against PRRS viruses in a porcine animal vaccinated
therewith.
[0070] Examples of an antigenic epitope from a swine pathogen other
than a North American PRRS virus include, but are not limited to,
an antigenic epitope from a swine pathogen selected from the group
consisting of European PRRS, porcine parvovirus, porcine
circovirus, a porcine rotavirus, swine influenza, pseudorabies
virus, transmissible gastroenteritis virus, porcine respiratory
coronavirus, classical swine fever virus, African swine fever
virus, encephalomyocarditis virus, porcine paramyxovirus,
Actinobacillus pleuropneumoni, Bacillus anthraci, Bordetela
bronchiseptica, Clostridium haemolyticum, Clostridium perfringens,
Clostridium tetani, Escherichia coli, Erysipelothrix rhusiopathiae,
Haemophilus parasuis, Leptospira spp., Mycoplasma hyopneumoniae,
Mycoplasma hyorhinis, Pasteurella haemolytica, Pasteurella
multocida, Salmonella choleraesuis, Salmonella typhimudum,
Streptococcus equismilis, and Streptococcus suis. Nucleotide
sequences encoding antigenic epitopes from the aforementioned swine
pathogens are known in the art and can be obtained from public gene
databases such as GenBank
(http/www.ncbi.nlm.nih.gov/Web/Genbank/index.html) provided by
NCBI.
[0071] If the heterologous antigenic epitopes are antigenic
epitopes from one or more other swine pathogens, then the isolated
polynucleotide molecule can further contain one or more mutations
that genetically disable the encoded PRRS virus in its ability to
produce PRRS. Such isolated polynucleotide molecules and the
viruses they encode are useful for preparing vaccines for
protecting swine against the swine pathogen or pathogens from which
the heterologous antigenic epitopes are derived.
[0072] The present invention provides a genetically modified North
American PRRS virus able to elicit an effective immunoprotective
response against infection by a PRRS virus in a porcine animal.
Such isolated polynucleotide molecules and the viruses they encode
are useful for preparing dual-function vaccines for protecting
swine against infection by both a North American PRRS virus and the
swine pathogen or pathogens from which the heterologous antigenic
epitopes are derived.
[0073] The isolated polynucleotide molecules of the present
invention comprising nucleotide sequences encoding heterologous
antigenic epitopes can be prepared as described above based on the
sequence encoding a North American PRRS virus described herein
using known techniques in molecular biology.
[0074] In one embodiment, the additional nucleotide sequences that
each encode a heterologous antigenic epitope are inserted into the
DNA sequence encoding an infectious RNA molecule encoding a North
American PRRS virus within an open reading frame encoding for a
PRRS virus protein. In a non-limiting embodiment, the additional
nucleotide sequences are inserted in ORF 1a or ORF 1b. In another
embodiment, the additional nucleotide sequences are inserted within
sequences encoding for the nonstructural protein 2 (nsp2), which is
part of ORF 1a. In a separate embodiment, the additional nucleotide
sequences are inserted within the region encoding the hypervariable
C-terminal portion of nsp2. In a further embodiment, the additional
nucleotide sequences are inserted between the DNA sequence encoding
amino acids 628 and 759 in the hypervariable region in the
nonstructural protein 2 coding region of ORF1a within said DNA
sequence, which is within the region encoding the hypervariable
C-terminal portion of nsp2. See FIG. 4.
[0075] The hypervariable region of nsp2 corresponds approximately
to genome coordinates 2720-3980 in P129. See FIG. 4.
[0076] In a separate embodiment, the additional nucleotide
sequences that each encode a heterologous antigenic epitope are
inserted into the DNA sequence encoding an infectious RNA molecule
encoding a North American PRRS virus within the sequences encoding
any of ORFs 1a, 1b, 2, 3, 4, 5, 6, or 7. See FIG. 4.
[0077] In another embodiment, a heterologous antigenic epitope of
the genetically modified North American PRRS virus of the present
invention is a detectable antigenic epitope. Such isolated
polynucleotide molecules and the North American PRRS viruses they
encode are useful, interalia, for studying PRRS infections in
swine, determining successfully vaccinated swine, and/or for
distinguishing vaccinated swine from swine infected by a wild-type
PRRS virus. Preferably, such isolated polynucleotide molecules
further contain one or more mutations that genetically disable the
encoded PRRS virus in its ability to produce PRRS, and more
preferably are able to elicit an effective immunoprotective
response in a porcine animal against infection by a PRRS virus.
[0078] Heterologous antigenic epitopes that are detectable, and the
sequences that encode them, are known in the art. Techniques for
detecting such antigenic epitopes are also known in the art and
include serological detection of antibody specific to the
heterologous antigenic epitope by means of, for example, Western
blot, ELISA, or fluorescently labeled antibodies capable of binding
to the antibodies specific to the heterologous antigenic epitope.
Techniques for serological detection useful in practicing the
present invention can be found in texts recognized in the art, such
as Coligan, J. E., et al (eds), 1998, Current Protocols in
Immunology, John Willey & Sons, Inc., which is hereby
incorporated by reference in its entirety. Alternatively, the
heterologous antigenic epitope itself can be detected by, for
example, contacting samples that potentially comprise the antigenic
epitope with fluorescently-labeled antibodies or
radioactively-labeled antibodies that specifically bind to the
antigenic epitopes.
[0079] The present invention further provides an isolated
polynucleotide molecule comprising a DNA sequence encoding an
infectious RNA molecule which encodes a genetically modified North
American PRRS virus that detectably lacks a North American PRRS
virus antigenic epitope, wherein the DNA sequence encoding the RNA
molecule encoding the North American PRRS virus is SEQ ID NO:1 or a
sequence homologous thereto, except that it lacks one or more
nucleotide sequences encoding a detectable North American PRRS
virus antigenic epitope. Such isolated polynucleotide molecules are
useful for distinguishing between swine infected with a recombinant
North American PRRS virus of the present invention and swine
infected with a wild-type PRRS virus. For example, animals
vaccinated with killed, live or attenuated North American PRRS
virus encoded by such an isolated polynucleotide molecule can be
distinguished from animals infected with wild-type PRRS based on
the absence of antibodies specific to the missing antigenic
epitope, or based on the absence of the antigenic epitope itself:
If antibodies specific to the missing antigenic epitope, or if the
antigenic epitope itself, are detected in the animal, then the
animal was exposed to and infected by a wild-type PRRS virus. Means
for detecting antigenic epitopes and antibodies specific thereto
are known in the art, as discussed above. Preferably, such an
isolated polynucleotide molecule further contains one or more
mutations that genetically disable the encoded PRRS virus in its
ability to produce PRRS. More preferably, the encoded virus remains
able to elicit an effective immunoprotective response against
infection by a PRRS virus.
[0080] B. Vaccines and Uses Thereof.
[0081] The present invention also provides vaccines comprising
North American PRRS viruses, including genetically modified North
American PRRS viruses disabled in their ability to produce PRRS in
a swine animal as described herein; infectious RNA molecules and
plasmids encoding such North American PRRS viruses as described
herein; and viral vectors encoding such North American PRRS viruses
and isolated RNA molecules as described herein.
[0082] In one embodiment, the subject invention provides a vaccine
comprising a genetically modified North American PRRS virus which
lacks at least one detectable antigenic epitope as described
herein, an infectious RNA molecule encoding such a genetically
modified North American PRRS virus, a plasmid as described herein
encoding such a genetically modified North American PRRS virus, or
a viral vector encoding such a genetically modified North American
PRRS virus, and a carrier acceptable for pharmaceutical or
veterinary use, in an amount effective to elicit an
immunoprotective response against PRRS virus infection in the
porcine animal.
[0083] In another embodiment, the subject invention provides a
vaccine comprising a genetically modified North American PRRS virus
comprising one or more detectable heterologous antigenic epitopes
as described herein, an infectious RNA molecule encoding such a
genetically modified North American PRRS virus, a plasmid as
described herein encoding such a genetically modified North
American PRRS virus, or a viral vector encoding such a genetically
modified North American PRRS virus, and a carrier acceptable for
pharmaceutical or veterinary use.
[0084] Such vaccines can be used to protect from infection a mammal
or a bird capable of being pathogenically infected by the pathogen
or pathogens from which the detectable heterologous antigenic
epitope(s) are derived. If such a vaccine comprises the genetically
modified North American PRRS virus, the genetic modification of the
North American PRRS virus preferably renders the virus unable to
cause PRRS in swine. Thus, such would provide a dual-vaccine for
swine, protecting swine from infection by the swine pathogen or
pathogens from which the heterologous antigenic epitope(s) are
derived as well as from infection by a PRRS virus. If the vaccine
comprises an infectious RNA molecule or a plasmid encoding a
genetically-modified North American PRRS virus comprising one or
more heterologous antigenic epitopes from another swine pathogen,
then the sequence encoding the infectious RNA molecule encoding the
genetically modified PRRS virus preferably comprises one or more
further mutations that genetically disable the encoded North
American PRRS virus so that it is unable to cause PRRS. In another
preferred embodiment, the encoded genetically modified, disabled
North American PRRS virus is able to elicit an immunoprotective
response against a PRRS infection in a swine animal, thus providing
a dual-vaccine for swine, able to protect swine from infection by
the swine pathogen or pathogens from which the heterologous
antigenic epitope(s) are derived as well as from infection by a
PRRS virus. All of these vaccines also further comprise a carrier
acceptable for veterinary use.
[0085] Vaccines of the present invention can be formulated
following accepted convention to include acceptable carriers for
animals, including humans (if applicable), such as standard
buffers, stabilizers, diluents, preservatives, and/or solubilizers,
and can also be formulated to facilitate sustained release.
Diluents include water, saline, dextrose, ethanol, glycerol, and
the like. Additives for isotonicity include sodium chloride,
dextrose, mannitol, sorbitol, and lactose, among others.
Stabilizers include albumin, among others. Other suitable vaccine
vehicles and additives, including those that are particularly
useful in formulating modified live vaccines, are known or will be
apparent to those skilled in the art, See, e.g., Remington's
Pharmaceutical Science, 18th ed., 1990, Mack Publishing, which is
incorporated herein by reference.
[0086] Vaccines of the present invention may further comprise one
or more additional immunomodulatory components such as, e.g., an
adjuvant or cytokine, among others. Non-limiting examples of
adjuvants that can be used in the vaccine of the present invention
include the RIBI adjuvant system (Ribi Inc., Hamilton, Mont.),
alum, mineral gels such as aluminum hydroxide gel, oil-in-water
emulsions, water-in-oil emulsions such as, e.g., Freund's complete
and incomplete adjuvants, Block copolymer (CytRx, Atlanta Ga.),
QS-21 (Cambridge Biotech Inc., Cambridge Mass.), SAF-M (Chiron,
Emeryville Calif.), AMPHIGEN.RTM. adjuvant, saponin, Quil A or
other saponin fraction, monophosphoryl lipid A, and Avridine
lipid-amine adjuvant. Non-limiting examples of oil-in-water
emulsions useful in the vaccine of the invention include modified
SEAM62 and SEAM 1/2 formulations. Modified SEAM62 is an
oil-in-water emulsion containing 5% (v/v) squalene (Sigma), 1%
(v/v) SPAN.RTM. 85 detergent (ICI Surfactants), 0.7% (v/v)
TWEEN.RTM. 80 detergent (ICI Surfactants), 2.5% (v/v) ethanol, 200
.mu.g/ml Quil A, 100 .mu.g/ml cholesterol, and 0.5% (v/v) lecithin.
Modified SEAM 1/2 is an oil-in-water emulsion comprising 5% (v/v)
squalene, 1% (v/v) SPAN.RTM. 85 detergent, 0.7% (v/v) Tween 80
detergent, 2.5% (v/v) ethanol, 100 .mu.g/ml Quil A, and 50 .mu.g/ml
cholesterol. Other immunomodulatory agents that can be included in
the vaccine include, e.g., one or more interleukins, interferons,
or other known cytokines.
[0087] Vaccines of the present invention can optionally be
formulated for sustained release of the virus, infectious RNA
molecule, plasmid, or viral vector of the present invention.
Examples of such sustained release formulations include virus,
infectious RNA molecule, plasmid, or viral vector in combination
with composites of biocompatible polymers, such as, e.g.,
poly(lactic acid), poly(lactic-co-glycolic acid), methylcellulose,
hyaluronic acid, collagen and the like. The structure, selection
and use of degradable polymers in drug delivery vehicles have been
reviewed in several publications, including A. Domb et al., 1992,
Polymers for Advanced Technologies 3: 279-292, which is
incorporated herein by reference. Additional guidance in selecting
and using polymers in pharmaceutical formulations can be found in
texts known in the art, for example M. Chasin and R. Langer (ads),
1990, "Biodegradable Polymers as Drug Delivery Systems" in: Drugs
and the Pharmaceutical Sciences, Vol. 45, M. Dekker, NY, which is
also incorporated herein by reference. Alternatively, or
additionally, the virus, plasmid, or viral vector can be
microencapsulated to improve administration and efficacy. Methods
for microencapsulating antigens are well-known in the art, and
include techniques described, e.g., in U.S. Pat. No. 3,137,631;
U.S. Pat. No. 3,959,457: U.S. Pat. No. 4,205,060; U.S. Pat. No.
4,606,940; U.S. Pat. No. 4,744,933; U.S. Pat. No. 5,132,17; and
International Patent Publication WO 95/28227, all of which are
incorporated herein by reference.
[0088] Liposomes can also be used to provide for the sustained
release of virus, plasmid, or viral vector. Details concerning how
to make and use liposomal formulations can be found in, among other
places, U.S. Pat. No. 4,016,100; U.S. Pat. No. 4,452,747; U.S. Pat.
No. 4,921,706; U.S. Pat. No. 4,927,637; U.S. Pat. No. 4,944,948;
U.S. Pat. No. 5,008,050; and U.S. Pat. No. 5,009,956, all of which
are incorporated herein by reference.
[0089] An effective amount of any of the above-described vaccines
can be determined by conventional means, starting with a low dose
of virus, plasmid or viral vector, and then increasing the dosage
while monitoring the effects. An effective amount may be obtained
after a single administration of a vaccine or after multiple
administrations of a vaccine. Known factors can be taken into
consideration when determining an optimal dose per animal. These
include the species, size, age and general condition of the animal,
the presence of other drugs in the animal, and the like. The actual
dosage is preferably chosen after consideration of the results from
other animal studies.
[0090] One method of detecting whether an adequate immune response
has been achieved is to determine seroconversion and antibody titer
in the animal after vaccination. The timing of vaccination and the
number of boosters, if any, will preferably be determined by a
doctor or veterinarian based on analysis of all relevant factors,
some of which are described above.
[0091] The effective dose amount of virus, infectious RNA molecule,
plasmid, or viral vector, of the present invention can be
determined using known techniques, taking into account factors that
can be determined by one of ordinary skill in the art such as the
weight of the animal to be vaccinated. The dose amount of virus of
the present invention in a vaccine of the present invention
preferably ranges from about 10.sup.1 to about 10.sup.9 pfu (plaque
forming units), more preferably from about 10.sup.2 to about 10
pfu, and most preferably from about 10.sup.3 to about 10.sup.7 pfu.
The dose amount of a plasmid of the present invention in a vaccine
of the present invention preferably ranges from about 0.1 .mu.g to
about 100 mg, more preferably from about 1 .mu.g to about 10 mg,
even more preferably from about 10 .mu.g to about 1 mg. The dose
amount of an infectious RNA molecule of the present invention in a
vaccine of the present invention preferably ranges from about 0.1
.mu.g to about 100 mg, more preferably from about 1 .mu.g to about
10 mg, even more preferably from about 10 .mu.g to about 1 mg. The
dose amount of a viral vector of the present invention in a vaccine
of the present invention preferably ranges from about 10.sup.1 pfu
to about 10.sup.9 pfu, more preferably from about 10.sup.2 pfu to
about 10 pfu, and even more preferably from about 10.sup.3 to about
10.sup.7 pfu. A suitable dosage size ranges from about 0.5 ml to
about 10 ml, and more preferably from about 1 ml to about 5 ml.
[0092] It is to be understood that the term "North American PRRS
viruses of the present invention" and like terms, unless otherwise
indicated, include any of the genetically modified North American
PRRS viruses described herein as well as the unmodified North
American PRRS virus described herein encoded by SEQ ID NO:1 or a
sequence homologous thereto.
[0093] C. Diagnostic Kits
[0094] The present invention also provides diagnostic kits. The kit
can be valuable for differentiating between porcine animals
naturally infected with a field strain of a PRRS virus and porcine
animals vaccinated with any of the vaccines described herein. The
kits can also be of value because animals potentially infected with
field strains of PRRS virus can be detected prior to the existence
in the absence of clinical symptoms and removed from the herd, or
kept in isolation away from naive or vaccinated animals. The kits
include reagents for analyzing a sample from a porcine animal for
the presence of antibodies to a PRRS virus. Diagnostic kits of the
present invention can include as a component a peptide or peptides
which comprise all or a portion of a protein sequence which is no
longer present in a genetically modified North American PRRS virus
which may optionally comprise one or more detectable heterologous
antigenic epitopes. Kits of the present invention can alternatively
include as a component a peptide which is a fusion protein. The
term "fusion peptide" or "fusion protein" for purposes of the
present invention means a single polypeptide chain consisting of at
least a portion of a PRRS virus protein and a heterologous peptide
or protein.
[0095] D. Plasmids Encoding a North American PRRS Virus or a
Genetically Modified North American PRRS Virus.
[0096] The present invention also provides any of the
above-described isolated polynucleotide molecules in the form of a
plasmid capable of expressing the North American PRRS virus encoded
thereby.
[0097] Plasmids of the present invention can express the encoded
North American PRRS virus outside of a living organism, to produce
North American PRRS viruses of the invention useful, inter alia,
for preparing vaccines. In one embodiment, a plasmid of the present
invention capable of expressing a North American PRRS virus outside
of a living organism is a plasmid wherein transcription of viral
RNA therefrom occurs in vitro (i.e. extracellularly); the resulting
viral RNA molecule is transfected into a suitable host cell using
known mechanisms of transfection, such as electroporation,
lipofection (in some cases using a commercially available reagent,
such as Lipofectin.TM. (Life Technologies Inc., Rockville, Md.,
USA)), or DEAE dextran mediated transfection. Other methods of
transfection are known in the art and can be employed in the
present invention. An example of such a plasmid for in vitro
transcription of North American PRRS viral RNA is the plasmid
pT7P129A (ATCC Accession No. 203488). Any promoter useful for in
vitro transcription can be used in such plasmids of this invention.
T7 is one such promoter, but other promoters can be used, such as
an SP6 promoter or a T3 promoter. The sequences of such promoters
can be artificially synthesized or cloned from commercially
available plasmids. Suitable plasmids for preparing such plasmids
capable of expressing North American PRRS virus include, but are
not limited to, general purpose cloning vector plasmids such as
pCR2.1 (Invitrogen, Carlsbad, Calif., USA), pBR322, and pUC18. A
nucleotide sequence of the present invention encoding the North
American PRRS virus can be inserted into any of these plasmids
using known recombinant techniques. Other plasmids into which the
polynucleotide molecules of the present invention can be inserted
will be recognized by those of ordinary skill in the art.
[0098] Suitable conditions for in vitro transcription of viral RNA
from any of the above-described recombinant plasmids comprising a
DNA sequence encoding an infectious RNA molecule encoding a North
American PRRS virus depends on the type of plasmid, for example,
its particular promoter, and can be ascertained by one of ordinary
skill in the art. For example, if a plasmid of the present
invention is based on a pCR2.1 plasmid comprising a T7 promoter,
then an example of suitable conditions for in vitro transcription
includes reacting the plasmid with T7 RNA polymerase and
ribonucleotides in a standard buffer and incubating the reaction at
37.degree. C. for about 30 minutes. In some cases, commercial kits
are available for transcribing RNA from a particular plasmid, and
such kits can be used in the present invention. The reaction
mixture following transcription can be directly transfected into a
suitable host cell without purification, or the transcribed North
American PRRS virus RNA can be purified by known RNA purification
techniques, for example by organic (e.g. phenol) extraction and
alcohol (e.g. ethanol or isopropanol) precipitation, prior to
transfection.
[0099] Transcription of the DNA sequence encoding an infectious RNA
molecule encoding a North American PRRS virus, and further
comprising one or more additional nucleotide sequences that each
encode a heterologous antigenic epitope, results in the formation
of a genomic and subgenomic RNA molecules. In one embodiment, at
least one heterologous antigenic epitope is translated directly
from the genomic RNA molecule. In another embodiment, at least one
heterologous antigenic epitope is translated from a subgenomic RNA
molecule that is synthesized from the genomic RNA.
[0100] The term "translation" for purposes of the present invention
means the synthesis of protein from nucleotides such as an RNA
molecule. In one embodiment, translation of the genomic or a
subgenomic RNA molecule encoding a heterologous antigenic epitope
results in synthesis of a peptide or protein consisting of the
heterologous antigenic epitope itself. In another embodiment,
translation of the genomic or a subgenomic RNA molecule results in
synthesis of a fusion peptide or protein. The term "fusion peptide
or protein" for purposes of the present invention means a single
polypeptide chain consisting of at least a portion of a PRRS virus
protein and at least one heterologous antigenic epitope.
[0101] Practically any mammalian or avian cell culture can be
transfected with the North American PRRS virus RNA obtained as
described above in order to generate a first round of North
American PRRS virions. An example of cells which one might find
particularly useful because of their ready availability and ease of
use are BHK (baby hamster kidney) cells. However, if one wishes to
generate a cell culture capable of sustained production of North
American PRRS virions, then porcine alveolar macrophage cells or
MARC-145 cells (Kim, H. S., et al., supra) are preferred since
these cells excrete high levels of new generation PRRS virions
subsequent to PRRS virus infection. Other cell lines derived from
the MA-104 cell line may also be used for sustained generation of
North American PRRS virions of the present invention. Primary
porcine alveolar macrophage cells can be obtained by lung lavages
from pigs, and the MARC-145 monkey kidney cell line can be obtained
from the National Veterinary Services Laboratories otherwise known
as NVSL (Ames, Iowa, USA).
[0102] In another embodiment, a plasmid capable of expressing a
North American PRRS virus of the present invention outside of a
living organism is a plasmid which is transfected into a suitable
host cell, for example by electroporation or lipofection,
transcription of the infectious RNA molecule and expression of the
North American PRRS virus therefrom occurring within the
transfected host cell. The transfected host cell therefore
generates North American PRRS virions. Such a completely cellular
method has heretofore never been disclosed or suggested for any
virus within the order of Nidovirales. Because of possible cryptic
splicing and termination sequences present in the RNA genome of
viruses of the Nidovirales order, a completely cellular method of
expressing a Nidovirales virus was believed unlikely. Cryptic
sequences include RNA splice donor and splice acceptor sequences,
which could cause inappropriate splicing of the RNA transcript, as
well as polyadenylation sequences, which could cause premature
termination by the cellular RNA polymerase II. The present
invention demonstrates, however, that the presence of such
sequences in a plasmid comprising a cDNA clone of a Nidovirus does
not prevent the plasmid's ability to express the Nidovirus when the
plasmid is directly transfected into a suitable host cell.
[0103] Accordingly, the subject invention also provides plasmids
and a completely cellular method for expressing a Nidovirales
virus, wherein the plasmid comprises: a) a DNA sequence encoding an
infectious RNA molecule encoding the Nidovirales virus; and b) a
promoter capable of transcribing said encoding sequence in a cell,
wherein said promoter is in operative association with the DNA
sequence encoding the infectious RNA molecule. The method comprises
transfecting a suitable host cell with such a plasmid, subjecting
the transfected host cell to conditions suitable for expression of
gene sequences transfected therein, and collecting the expressed
Nidovirales virus therefrom. An example of a plasmid suitable for
completely cellular expression of North American PRRS virus outside
of a living organism is the plasmid pCMV-S-P129 (ATCC Accession No.
203489). In a preferred embodiment, the promoter of such a plasmid
is a CMV promoter. In a preferred embodiment, a plasmid of the
invention suitable for a completely cellular method of expressing a
Nidovirales virus comprises a eukaryotic promoter, such as a CMV
promoter, immediately upstream and adjacent to the nucleotide
sequence encoding the Nidovirales virus. In a preferred embodiment,
the nucleotide sequence encoding the Nidovirales virus encodes a
PRRS virus, either European or North American. Other examples of
Nidovirales viruses that can be expressed by means of the
above-described completely cellular method include other
Arteriviruses such as, equine arteritis virus, lactate
dehydrogenase-elevating virus, and simian haemorrhagic fever virus;
viruses that are members of the genus Coronaviridae, such as, but
not limited to, feline infectious peritinitis virus, feline enteric
coronavirus, canine coronavirus, bovine coronavirus, porcine
respiratory coronavirus, turkey coronavirus, porcine transmissible
gastroenteritis virus, human coronavirus, murine hepatitis virus,
and avian infectious bronchitis virus; and members of the genus
Toroviridae, such as, but not limited to, Berne virus, Breda virus,
and human torovirus. Thus, plasmids suitable for completely
cellular expression comprising a nucleotide sequence encoding one
of these viruses are also encompassed by the present invention.
[0104] Suitable plasmids that can be used to prepare recombinant
plasmids of the present invention for completely cellular
expression outside of a living organism of a Nidovirales virus,
such as a PRRS virus, include virtually any plasmid useful for
transfection and expression in eukaryotic cells. An examples of a
plasmid suitable for preparing recombinant plasmids of the present
invention for completely cellular expression of a Nidovirales virus
is the plasmid pCMVbeta (Clontech, Palo Alto, Calif., USA). Other
plasmids which are able to transfect and express genes in
eukaryotic cells which can be used to prepare plasmids of the
present invention include, but are not limited to, pcDNA3.1,
pRc/RSV, and pZeoSV2 (all from Invitrogen); and pCMV-Sports and
pSV-Sport1 (both from Life Technologies Inc.). However, almost any
eukaryotic expression vector will work for the present invention.
Constructs based on cosmids can also be used for completely
cellular ex vive expression of a Nidovirales virus.
[0105] Suitable host cells for the completely cellular method of
the present invention for expressing PRRS virus include porcine
alveolar macrophage cells and the MARC-145 cells, described above.
Methods of transfecting these cells with a plasmid are basically
the same as those methods for transfecting cells with viral ANA
described above. Such methods include, but are not limited to,
electroporation, lipofection, DEAE dextran mediated transfection,
and calcium phosphate coprecipitation.
[0106] Once host cells, such as porcine alveolar macrophage cells
or a MARC-145 cells, have been transfected according to the subject
invention, either with viral RNA or with a plasmid comprising a
nucleotide sequence encoding a virus, then the cells can be frozen
at about -80.degree. C. or below for storage for up to several
years. For longer periods of time, i.e. decades, storage in liquid
nitrogen is preferred. If relatively frequent use of the encoded
virus is envisioned, then cells hosting the virus can also be
maintained (unfrozen) in culture using known techniques, for
shorter periods of time. Moreover, viral particles excreted by such
cells can be stored frozen at about -80.degree. C. or below as a
source of virus. Transfection of such cell lines with the
polynucleotide molecule encoding the virus can be confirmed if
desired, for example, by testing exhausted medium excreted by the
cell line for a PRRS virus antigen using an immunofluorescent
antibody test. Antibodies which are specific for PRRS virus
antigens are known in the art (see, e.g., Collins, E. J., et al.,
WO 93/03760 Mar. 4, 1993).
[0107] In another embodiment, a plasmid of the present invention
comprising a nucleotide sequence encoding a North American PRRS
virus is suitable for in vive expression of the North American PRRS
virus, i.e. expression in a living organism. Plasmids which can be
used for preparing recombinant plasmids for in vivo expression of a
North American PRRS virus include, but are not limited to the
plasmids capable of transfecting eukaryotic cells described above,
such as pCMVbeta.
[0108] Animals that can be transfected with plasmids of the present
invention include mammals and birds. If the animal is other than a
porcine animal, for example, a mallard duck, then the plasmid can
comprise a nucleotide sequence encoding a North American PRRS virus
comprising further antigenic epitopes from pathogens which are
capable of pathogenically infecting the animal; in such a case, the
plasmid will encode a North American PRRS virus serving as a vector
for transporting epitopes into the animal. If the animal is a
porcine animal, then the plasmid can usefully encode any of the
North American PRRS viruses described herein, including the
genetically-modified North American PRRS viruses described
herein.
[0109] E. Viral Vectors Encoding a North American PRRS Virus,
Including Viral Vectors Encoding Genetically Modified North
American PRRS Viruses:
[0110] The present invention also provides viral vectors comprising
a DNA sequence encoding an infectious RNA molecule encoding any of
the North American PRRS viruses described herein, including the
genetically-modified North American PRRS viruses described herein.
Such viral vectors are useful for transfecting eukaryotic cells for
production of PRRS viruses of the present invention outside of a
living organism, or for transfecting swine, or other mammals, or
avians, with the sequence encoding the North American PRRS virus,
for in vive expression of the North American PRRS virus
therein.
[0111] Some examples of viruses that can be used as vectors for
preparing the viral vectors of the present invention include, but
are not limited to, swine viruses such as, but not limited to,
swine pox virus, pseudorabies virus, or African swine fever virus.
Such swine viruses can be obtained from The National Veterinary
Services Laboratories (Ames, Iowa, USA) of the United States
Department of Agriculture; the American Type Culture Collection,
otherwise known as the ATCC (Manassas, Va., USA); and other known
sources. Recombinant viral vectors based on suitable swine viruses
such as the aforementioned swine viruses are useful for
transfecting swine animals with a nucleotide sequence encoding a
North American PRRS virus of the present invention.
[0112] Viral vectors comprising a DNA sequence encoding an
infectious RNA molecule encoding a North American PRRS virus of the
present invention based on these and other viruses can be prepared
using known recombinant techniques described in texts such as those
cited previously in this application.
[0113] F. Transfected Host Cells Encoding or a Genetically Modified
North American PRRS Viruses.
[0114] The present invention also provides transfected host cells
that comprise a DNA sequence encoding an infectious RNA molecule
encoding any of the North American PRRS viruses described herein,
including the genetically-modified North American PRRS viruses
described herein, which transfected host cells are capable of
expressing the North American PRRS virus. Such transfected host
cells are useful for producing North American PRRS viruses of the
present invention. Examples of transfected host cells of the
present invention include the transfected porcine alveolar
macrophage cells and the transfected MARC-145 cells described
above.
[0115] Other transfected host cells of the invention include, but
are not limited to, transfected MA-104 cells and other derivatives
of MA-104 cells that are transfected; transfected Baby Hamster
Kidney (BHK) cells; transfected Chinese Hamster Ovary (CHO) cells;
and African Green Monkey kidney cells other than MA-104 cells or
MARC-145 cells, such as VERO cells; that are transfected.
[0116] G. North American PRRS Viruses, Including Genetically
Modified North American PRRS Viruses:
[0117] The present invention also provides North American PRRS
viruses as described herein, including genetically-modified North
American PRRS viruses as described herein, expressed and/or encoded
by any of the above-described isolated polynucleotide molecules,
RNA molecules, plasmids, viral vectors, or transfected host
cells.
[0118] In certain situations, for example where the North American
PRRS virus is to be used in a vaccine for swine and the North
American PRRS virus has not been genetically modified as described
above so as to be unable to cause PRRS, it is desirable to treat
the North American PRRS virus, for example by inactivating or
attenuating it, so that it is unable to cause PRRS in swine to
which it is administered. Known methods can be used to inactivate a
North American PRRS virus of the present invention so that it is
unable to cause PRRS in an animal. Examples of such methods
include, but are not limited to, treatment with formaldehyde, BEI
(binary ethyleneimine), or BPL (beta-propiolactone). Methods of
attenuation are also known in the art, and such methods can be used
to attenuate a North American PRRS virus of the present invention.
A North American PRRS virus of the present invention can, for
example, be attenuated by serial passage in cell culture.
[0119] If a North American PRRS virus of the present invention is
for use in an animal other than a porcine animal, or if it has been
genetically modified as described herein so that it is unable to
produce PRRS in a porcine animal, then it is not necessary to treat
the virus as described in the preceding paragraph prior to using it
in a vaccine.
[0120] The following examples are provided to merely illustrate
aspects of the subject invention. They are not intended, and should
not be construed, to limit the invention set forth in the claims
and more fully described herein.
EXAMPLES
Example 1
Preparation of an Infectious cDNA Clone of a North American PRRS
Virus Isolate
[0121] Source of PRRS Virus and MARC-145 Cells:
[0122] A North American PRRS virus isolate designated P129 was
obtained from Drs. Gregory W. Stevenson, William G. Van Alstine,
and Charles L. Kanitz of Purdue University's Animal Disease
Diagnostic Laboratory in West Lafayette, Ind. The P129 virus was
originally isolated in the autumn of 1995 from a swine herd in
southern Indiana experiencing a severe PRRS outbreak. This farm had
no previous history of PRRS problems or PRRS vaccination. The P129
isolate was more virulent than several other field isolates from
the same time period and geographic area, in that it produced more
severe and more consistent respiratory disease in young pigs. The
virus was initially isolated on primary porcine alveolar macrophage
(the natural host cell), and subsequently passaged on MARC-145
cells (Kim et al., 1993). Genes encoding structural proteins of
P129 were found to be homologous to corresponding known North
American PRRS gene sequences.
[0123] The MARC-145 cell line that was used to propagate PRRS
viruses is a clone of the MA-104 Rhesus Macaque Monkey Kidney cell
line. The MARC-145 cells were obtained from the National Veterinary
Services Laboratories (NVSL, Ames, Iowa) of the USDA. These cells
have been tested and found negative for mycoplasmas and for common
porcine extraneous agents. MARC-145 cells are routinely grown at 37
C. in OptiMEM (Life Technologies Inc.) with 2% fetal bovine serum
and antibiotics.
[0124] Five biological clones were plaque purified from the P129
virus stock, and these were designated P129A through P129E. Plaque
purification was carried out by infecting monolayers of MARC-145
cells with P129 virus, adding an overlay of OptiMEM containing
1.25% SeaPlaque agarose (FMC BioProducts), 2% fetal bovine serum,
and antibiotics. Plaques were clearly visible following incubation
for 7 days, when 5 well-isolated plaques were picked and passaged
onto fresh MARC-145 monolayers. When cytopathic effect (virus
induced cell death) became apparent the progeny virus from each of
these cultures was subjected to another round of plaque
purification. One well-isolated plaque from each of the five clones
was picked and expanded to produce large stocks. The 5 clones were
tested for virulence in young pigs, either individually (clones A
and E) or in combination (clones B-D, or clones A-E). In all cases,
the plaque purified virus replicated well in pigs and caused
clinical disease. The severity of clinical symptoms was less than
that caused by the uncloned P129 virus, even when all five clones
were used together. P129A was chosen for sequencing, and was used
in subsequent molecular manipulations.
[0125] Determination of the Genome Sequence of P129A:
[0126] Plaque purified virus P129A was used for sequence
determination after 10 serial passages from the pig (including two
plaque purifications and one subsequent passage). SEQ ID NO:1 shows
the cDNA sequence corresponding to the P129A RNA genome. The genome
is 15,395 nucleotides in length (excluding the polyadenosine tail),
begins with ATGACGTA, and ends with CCGCAATT. A typical
polyadenosine tail of 55 residues is also provided in SEQ ID
NO:1.
[0127] For the structural genes of P129A (ORFs 2 through 7), which
comprise the 3' 20% of the genome, various PCR primers were chosen
based on several partial cDNA sequences of other North American
PRRS virus isolates available in the public DNA sequence database
GenBank (for example PRU00153). Purified viral RNA was reverse
transcribed into cDNA using reverse transcriptase and random
hexamer primers. This cDNA was then used in PCR with gene-specific
primers. PCR products were excised from gels and T/A cloned into
plasmid pCR2.1 (Invitrogen). For each primer pair, multiple
plasmids (from independent PCR reactions) were DNA sequenced.
Sequences were assembled using the Seqman program from the
Lasergene package (DNASTAR, Inc). This permitted completing the
sequence of positions 11,992 through 15,347 of the P129A
genome.
[0128] Also in the GenBank database are a series of short sequences
(approximately 218 nucleotides total) which comprise a portion of
the ORF 1b gene of several isolates of PRRS virus. One of these
(PPSSEQB) was used to design PCR primers (forward
5'-ACAGTTTGGTGATTATG-3' (SEQ ID NO:10), corresponding to positions
9063-9080; reverse 5'-CAGATTCAGATGTTCAA-3' (SEQ ID NO: 1),
corresponding to positions 9252-9268). These amplified a 206
nucleotide fragments, which includes 171 nucleotides of new
sequence from the P129A ORF1b gene, corresponds to positions 9081
to 9251. A new forward primer was designed within this region
(5'-ACCTCGTGCTGTATGCOGAATCTC-3' (SEQ ID NO:12), positions
9201-9224), and a matching primer was designed within ORF1b
immediately upstream of ORF2 (5'-TCAGGCCTAAAGTTGGTTCAATGA-3' (SEQ
ID NO:13), positions 12,027-12,050). These primers were used in
RT-PCR to amplify a 2850 nucleotide fragment of ORF1b,
corresponding to positions 9201-12,050 of the P129A genome.
[0129] During RT-PCR amplification of ORF5 of another North
American field isolate of PRRS virus, a minor band was seen which
was smaller than the expected size. This was sequenced and found to
have limited homology with ORF1a of Lelystad virus (resulting from
false priming). New primers within this region were chosen to
amplify P129A (forward 5'-GATGACTGGGCTACTGACGAGGAT-3' (SEQ ID
NO:14), corresponding to positions 1587-1610; reverse
5'-AGAGCGGCTGGGATGACACTG-3' (SEQ ID NO:15), corresponding to
positions 1877-1897). In addition to the product of 311 nucleotides
(266 nucleotides of new P129A sequence between the primers
corresponding to positions 1611-1876), a larger minor PCR product
of 701 nucleotides was cloned and sequenced (656 nucleotides of new
P129A sequence between the primers corresponding to positions
1611-2264). The larger band results from false priming of the
reverse primer at positions 2265-2269.
[0130] The extreme 5' end of the genome of P129A was determined by
5' RACE (rapid amplification of cDNA ends) using a commercially
available kit (Life Technologies Inc). Two nested reverse primers
were chosen from within the known ORF1a sequence ("RACE2"
5'-CCGGGGAAGCCAGACGATTGAA-3' (SEQ ID NO:18), positions 1917-1938;
and "RACE3" 5'-AGGGGGAGCAAAGAAGGGGTCATC-3' (SEQ ID NO:17),
positions 1733-1756). RACE2 was used to prime cDNA synthesis, while
RACE3 was used in PCR. The resulting PCR products were cloned and
sequenced. The two longest products ended at precisely the same
base (position 1 in SEQ ID NO:1).
[0131] The large gap between known sequence in ORF1a and ORF1b was
bridged using long RT-PCR. Two new primers were used (forward
5'-AGCACGCTCTGGTGCAACTG-3' (SEQ 10 NO:18), positions 1361-1380;
reverse 5'-GCCGCGGCGTAGTATTCAG-3' (SEQ ID NO:19), positions
9420-9438). The resulting 8078 nucleotide RT-PCR product was cloned
and sequenced.
[0132] The extreme 3' end of the genome of P129A was determined by
ligating the 3' and 5' ends of the viral RNA together and using
RT-PCR to amplify the junction fragment. The resulting junction
fragments were cloned and sequenced. Briefly, RNA extracted from
pelleted virions was treated with tobacco acid pyrophosphatase (to
remove 5' cap structures), then self-ligated with T4 RNA ligase
(both from Epicentre Technologies). The primers used were
5'-CGCGTCACAGCATCACCCTCAG-3' (SEQ ID NO:20) (forward, positions
15,218-15,239) and either 5'-CGGTAGGTTGGTTAACACATGAGTT-3' (SEQ ID
NO:21) (reverse, positions 656-680) or
5'-TGGCTCTTCGGGCCTATAAAATA-3' (SEQ ID NO:22) (reverse, positions
337-359). All of the resulting clones were truncated at the 5' end
of the genome (the most complete came to within 57 nucleotides of
the actual 5' end, as revealed by 5' RACE), however two of these
clones contained the complete 3' end of the genome including the
polyadenosine tail (42 and 55 adenosine residues in length). This
completed the sequencing of the cDNA 15,450 base genome of PRRS
isolate P129A, including polyA tail, as shown in SEQ ID NO:1.
[0133] Creation of an Infectious Full-Length cDNA Clone of
P129A:
[0134] A full-length infectious cDNA clone of P129A, designated
pT7P129A, was assembled from four overlapping cloned RT-PCR
products. The four RT-PCR products were first T/A cloned into
plasmid pCR2.1 (Invitrogen) and transfected into Escherichia coli
strain DH5-alpha. Bacterial colonies were screened, and those which
contained inserts of the expected sizes in the "T7 to M13"
orientation were chosen for sequencing and further manipulation.
All four cloned RT-PCR products contained one or more non-silent
mutations (deviations from the consensus nucleotide sequence for
P129A of SEQ ID NO:1 which would result in a change in amino acid
sequence of the encoded ORFs). These non-silent mutations (save one
at position 12,622 in ORF 2) were repaired by subcloning fragments
from other cloned RT-PCR products. The four repaired subgenomic
clones were assembled into a full-length clone in a stepwise
manner, using available restriction sites (see FIG. 1). The 5' and
3' ends of the cDNA corresponding to the P129A genome in pT7P129A
were modified by the addition of a T7 promoter and appropriate
restriction endonuclease sites. The construction of pT7P129A is
described in further detail in the following paragraphs:
[0135] The 5' end of the genome (positions 1-1756), generated by
5'-RACE and cloned into pCR2.1 as described above, was modified to
include a T7 promoter immediately upstream of the cDNA
corresponding to the P129A genome and a PacI site for future
cloning. A 3-way ligation was performed using the 1216 bp
DsaI-BseRI fragment of this plasmid (containing bases 27-1242 of
P129A), the 4407 bp BseRI-XbaI fragment of the same plasmid
(containing bases 1243-1756 of P129A and the entire plasmid vector
up to the XbaI site), and the following synthetic double-stranded
adapter (SEQ ID NO: 23, first below and SEQ ID NO; 24, second
below):
TABLE-US-00002 5'-CTAGATTAATTAATACGACTCACTATAGGG
ATGACGTATAGGTGTTGGCTCTATGC-3' 3'-TAATTAATTATGCTGAGTGATATCCC
XbaI_____ T7 promoter PacI TACTGCATATCCACAACCGAGATACGGTGC-5'
_________________________DsaI P129A genome
[0136] The predicted transcript from the 17 promoter includes a
single "G" residue from the promoter immediately upstream of the
first "A" of the viral genome. A non-silent mutation at position
1230 (A to G) was repaired by replacing the 906 bp AatII--SacII
fragment (bases 740-1645) with the same fragment from another
clone. This plasmid was designated "pT7R3A-2".
[0137] The 8078 nucleotide PCR product described above was used to
cover bases 1361-9438 of the P129A genome. A 58 bp deletion
(positions 2535-2592) and 7 non-silent point mutations were
corrected by subcloning fragments from other cloned RT-PCR
products, yielding plasmid "pGAP10B-4". The 7837 bp Bsu36I-SpeI
fragment from this plasmid was ligated to the 5482 bp Bsu36I-SpeI
fragment from pT7R3A-2. The resulting plasmid "pT7RG" contains the
first 9438 bases of the P129A genome behind the T7 promoter.
[0138] The 2850 nucleotide fragment of ORF1b described above
(genome positions 9201-12,050) was corrected to repair non-silent
mutations and designated "p1B3A-2". The 2682 bp NdeI-SpeI fragment
of this plasmid was ligated to the 13,249 bp NdeI-SpeI fragment of
pT7RG to yield plasmid "pT71A1B", which contains the first 12,050
bases of the P129A genome.
[0139] The fourth and final fragment of the P129A genome was
derived by RT-PCR of ORFs 2 through 7, including the 3'
non-translated region and a portion of the polyA tail. The forward
primer was 5'-ACTCAGTCTAAGTGCTGGAAAGTTATG-3' (SEQ ID NO:25)
(positions 11,504-11,530) and the reverse primer was
5'-GGGATTTAAATATGCATTTTTTTTTTTTTTT
TTTTTTAATTGCGGCGGCCGCATGGTTCTCG-3' (SEQ ID NO:26). The reverse
primer contains the last 22 bases of the P129A genome (positions
15,374-15,395), a polyA tail of 21 bases, an NsiI site (ATGCAT) and
a SwaI site (ATTTAAAT). Non-silent point mutations and a single
base deletion were repaired by subcloning fragments from other
clones. An additional non-silent point mutation at position 12,622
(A to G) was inadvertently introduced at this stage. This results
in a change from glutamine to arginine near the C-terminus of the
ORF2 protein (amino acid residue 189 of the 256 amino acids in
ORF2, which does not affect the overlapping ORF 3). This mutation
had no apparent influence on viral growth, in cell culture or in
pigs, and was not repaired. This mutation served as a genetic
marker to distinguish virus derived from the cDNA clone from
possible contamination with parental P129A or other PRRS viruses.
The plasmid was designated "p2.sub.--7D-4". The structural genes of
P129A were added to the rest of the genome by ligating the 3678 bp
Eco47III-SpeI fragment of p2.sub.--7D-4 to the 15.635 bp
Eco47III-SpeI fragment of pT71A1B.
[0140] This yields the final construct "pT7P129A", which comprises
cDNA corresponding almost identically to the entire genome of P129A
(however, with only a 21 base polyA tail, as opposed to 55 base
potyA tail) behind a T7 promoter, cloned into the pCR2.1 vector
between unique restriction enzyme sites (PacI and SwaI). The total
length of pTP7129A is 19,313 bp, and it is stable in E. coli strain
DH5-alpha. pT7P129A contains an A to G non-silent point mutation at
position 12,622 that results in an arginine at position 189 of ORF2
rather than a glutamine (as is encoded by SEQ ID NO:1) and a silent
C to T mutation at position 1559. Neither of these mutations
affected viral growth under the conditions examined, both in cell
culture and in pigs. For example, pT7P129A was used for in vitro
transcription and the resulting RNA transcripts produced live North
American PRRS virus when transfected into MARC-145 cells, thus
demonstrating that this full-length clone is infectious.
[0141] In Vitro Transcription and Transfection of RNA
Transcripts:
[0142] In plasmid pT7P129A there are two T7 promoters in tandem
upstream of the viral genome. One of these is positioned
immediately upstream of the viral genome and was built into the PCR
primer as described above. The other is present in the pCR2.1
cloning vector and is located outside of the multiple cloning site
(initiating transcription 44 bases upstream of the viral genome).
PacI was used to cut between these T7 promoters prior to in vitro
transcription to generate a transcript that is closer to authentic
viral RNA (a single extra G immediately upstream the viral genome,
as opposed to 44 extra bases from the distal T7 promoter). In
addition, pT7P129A was cut with SwaI prior to in vitro
transcription. The resulting run-off transcripts include a 21 base
long polyA tail and nine non-PRRS nucleotides, including an Ns site
(which was not used to linearize the plasmid, since the site also
occurs once in the viral genome). The digested plasmid was purified
by phenol extraction and ethanol precipitation prior to use.
[0143] A commercial kit (T7 Cap-Scribe, Boehringer Mannheim) was
used for in vitro transcription. The DNA pellet from above,
containing about 0.6 .mu.g of PacI/SwaI digested pT7P129A, was
resuspended in 20 .mu.l of T7 Cap-Scribe buffer/T7 polymerase and
incubated at 37.degree. C. for 30 minutes. A portion of the
reaction was analyzed by agarose gel electrophoresis and shown to
contain full-length RNA transcripts in addition to the expected DNA
bands of 15,445 bp and 3868 bp. The in vitro transcription reaction
was used fresh, immediately following incubation, without
purification. Freshly confluent monolayers of MARC-145 cells were
washed once in OptiMEM (without serum), and covered with 1 ml per
35 mm well of OptiMEM (without serum) containing 500 .mu.g/ml DEAE
dextran (molecular weight approx. 500,000, Pharmacia Biotech). In
vitro transcription reaction (15 .mu.l) was added immediately.
After 1 hour at 37.degree. C., the transfection mixture was
removed, monolayers were washed once with PBS and overlaid with
1.25% SeaPlaque agarose (FMC corporation) in OptiMEM with 2% fetal
bovine serum and antibiotics. After 5 days at 37.degree. C., a
single plaque was visible. This virus was designated "rP129A-1" and
was expanded on MARC-145 cells and characterized in cell culture
and in pigs. Subsequent transfections of in vitro transcribed RNA
from pT7P129A, using both DEAE dextran and electroporation, have
yielded many additional plaques.
[0144] Characterization of Recombinant Virus rP129A-1:
[0145] There are no apparent differences in growth kinetics, yield,
or plaque morphology between cDNA-derived recombinant virus
rP129A-1 and its non-recombinant parent P129A. As discussed above,
there are two differences in nucleotide sequence between the coding
sequence of pT7P129A and the consensus sequence of P129A (shown in
SEQ ID NO:1). Firstly, at position 1559 pT7P129A contains a T,
whereas P129A contains a C (this is a silent mutation). Secondly,
at position 12,622 pT7P129A contains a G, whereas P129A contains an
A (this is the glutamine to arginine change in ORF2 described
above). In order to rule out the possibility that rP129A-1 is
actually a non-recombinant PRRS virus contaminant, RT-PCR and
sequencing were performed on the regions surrounding these two
differences in the case of both genetic markers, rP129A-1 was
identical to plasmid pT7P129A and different from parental virus
P129A, thus confirming that rP129A-1 is derived from the infectious
cDNA clone.
[0146] Characterization of Recombinant Virus rP129A-1 in Pigs:
[0147] The cDNA-derived virus rP129A-1 was compared to its
non-recombinant parent P129A for its ability to infect and cause
clinical disease in young pigs. Three groups of 10 pigs each from a
PRRS-negative herd were infected at 4 weeks of age with either
P129A, rP129A-1, or mock-infected with cell culture medium.
Clinical signs, rectal temperatures, and body weights were
monitored. Blood was collected on days 0, 2, 6, 10, and 13
post-infection for determination of serum viremia (by plaque assay
on MARC-145 cells, FIG. 2) and serum antibody (by ELISA using
HerdChek PRRS from IDEXX, FIG. 3). Gross and microscopic lesions of
the lung were observed upon necropsy. There were no significant
differences between the two virus-infected groups, indicating that
rP129A-1 replicates in pigs and causes clinical disease which is
quantitatively and qualitatively similar to its non-recombinant
parent virus.
Example II
Deletion of ORF7 (Nucleocapsid Gene) from the North American PRRS
Virus; Preparation of a Negatively-Marked, Replication-Defective
Vaccine Thereby
[0148] The viral nucleocapsid gene (ORF7) was partially deleted
from an infectious cDNA clone of the PRRS virus of the present
invention. The resulting recombinant modified PRRS virus would be
expected to be replication-defective in pigs. This recombinant
modified PRRS virus can be used as a vaccine to induce an immune
response to the other PRRS virus proteins without the risks of
clinical disease, spread to non-vaccinated animals, or reversion to
virulence associated with attenuated live vaccines. In addition to
being very safe, such a vaccine virus would also be "negatively
marked", in the sense that it would allow exposure to field
isolates of PRRS virus to be determined serologically, even in the
presence of antibody to the vaccine virus. Antibodies to the ORF7
protein are commonly found in the sera of PRRS virus-infected pigs,
whereas pigs vaccinated with an ORF7-deleted PRRSV would lack
antibodies to the ORF7 protein.
[0149] Deletion of ORF7 from an infectious clone was accomplished
as follows: Plasmid p2.sub.--7D-4 (see FIG. 1) was used as template
in PCR to amplify the 5' and 3' flanking regions upstream and
downstream of ORF7. The upstream flank forward primer
5'-ATTAGATCTTGC CACCATGGTGGGGAAATGCTTGAC-3' (SEQ ID NO:27) (which
binds to genome positions 13,776-13,791 near the beginning of ORF5
and contains additional restriction sites which are irrelevant to
the current cloning) and the upstream flank reverse primer
5'-CTTTACGCGTTTG CTTAAGTTATTTGGCGTATTTGACAAGGTTTAC-3' (SEQ ID
NO:28) (which binds to genome positions 14,857-14,902 at the
junction of ORFs 6 and 7) amplified a fragment of 1147 bp. The
reverse primer introduced MluI and AflII sites and a single base
change at position 14,874, destroying the ATG start codon for ORF7
without altering the tyrosine encoded in the overlapping ORF6. For
the downstream flank, the forward primer 5'-CAACAC
GCGTCAGCAAAAGAAAAAGAAGGGG-3' (SEQ ID NO:29) (positions
14,884-14,914 near the 5' end of ORF7, introduced an MluI site) and
reverse primer 5'-GCGCGTTGGCCGATTC ATTA-3' (SEQ ID NO:30)
(downstream of the viral genome in the pCR2.1 plasmid) amplified a
462 bp fragment. A 3-way ligation was performed, using the 611 bp
BstEII-MluI fragment of the upstream flank PCR product, the 575 bp
MluI-SpeI fragment of the downstream flank PCR product, and the
8653 bp BstEII-SpeI fragment from plasmid p2.sub.--7D-4 (all
fragments were gel purified following digestion). The resulting
plasmid p2.sub.--7Ddelta7+7023 was deleted in the first seven amino
acids of ORF7, and lacks a functional ATG start codon. Two new
restriction sites which are absent in both the viral genome and the
plasmid backbone, AlfII and MluI, have been inserted to facilitate
directional cloning of foreign genes into the space previously
occupied by the 5' end of ORF7.
[0150] The changes made in p2.sub.--7Ddelta7+7023 were incorporated
into a full-length genomic clone by ligating the 3683 bp
Eco47III-SpeI fragment of p2.sub.--7Ddelta7+7023 with the 15,214 bp
Eco47III-SpeI fragment of pCMV-S-p129. The resulting plasmid
pCMV-S-p129delta7+7023 was used to transfect cells.
[0151] Since nucleocapsid is essential for viral growth, it is
necessary to provide this protein in order to allow generation and
replication of an ORF7-deficient PRRS virus. This can be
accomplished using a helper virus or a complementing cell line, for
example. ORF7-expressing MARC-145 cell lines can be created by
stably transfecting cells with a plasmid containing both the ORF7
gene from P129A and the neomycin resistance gene. After selecting
for neomycin resistance using the antibiotic G418, single-cell
colonies can then be expanded and characterized. Clonal
MARC-145-derived cell lines that are positive for ORF7 expression
by both immunofluorescence and RT-PCR can be transfected with RNA
from pT7P129delta7 in order to generate ORF7-deficient P129
virus.
[0152] Similar strategies can be used to generate PRRS viruses
deficient in other structural genes (ORFs 2, 3, 4, 5, or 6), or
deficient in all or portions of non-structural genes 1a and 1b. In
addition, multiple deletions can be engineered into a single PRRS
virus, and these can be grown in complementing cells which provide
all necessary functions. Such gene-deficient PRRS viruses are
likely to be either partially or completely attenuated in pigs,
making them useful as vaccines against PRRS. They can also be used
to distinguish vaccinated animals from animals infected with a
wild-type PRRS virus as discussed above and/or as vectors for
vaccinating animals with epitopes of other porcine pathogens (see
Example III, below).
Example III
Insertion of Heterologous Genes into the North American PRRS Virus
Genome; Use of PRRS Virus as a Vector, and a Positively-Marked
North American PRRS Virus
[0153] In Example II, above, AflII and MluI restriction enzyme
sites were inserted into the region formerly occupied by the 5' end
of ORF7. These sites are absent in the P129A genome and in the
pCR2.1 and pCMV plasmids, and can be used in the directional
cloning of foreign (heterologous) genes into the viral genome for
expression. Potential leader-junction sites for transcription of
the ORF7 subgenomic RNA at positions 14,744-14,749 (ATAACC) and
14.858-14,863 (TAAACC) are not affected by deletion of the ORF7
coding sequence, and can function in transcription of a foreign
gene. Foreign (heterologous) genes can include genes from other
PRRS virus isolates or genotypes, and/or genes from other non-PRRS
pathogens, either pathogens that infect swine or pathogens that
infect mammals other than swine, or avians.
[0154] In addition, these foreign genes (or portions thereof) can
provide antigenic epitopes which are not normally found in swine.
Such epitopes can be used to "positively mark" a vaccine, so that
successful vaccination can be monitored serologically, even in the
presence of antibody to field or conventional vaccine strains of
PRRS virus. A positive marker needs not be a separate expression
cassette. An antigenic epitope can be fused to a structural gene of
the PRRS virus. For example, the upstream flank reverse primer
described in Example I, above, can be extended in such a way as to
add a carboxyl-terminal fusion of a non-PRRS virus antigenic
epitope to the ORF6 membrane protein. The presence of antibody to
this epitope in swine indicates successful vaccination.
Example IV
Cellular Expression of a PRRS Virus by Direct Transfection of cDNA
into Cells
[0155] The eukaryotic expression vector pCMV-MC1 (SEQ ID NO:31) was
derived from the commercially available plasmid pCMVbeta (Clontech)
by replacing the LacZ coding sequence between two Not I sites with
a linker containing Not I, EcoR V, Avr II, Bgl II, Cla I, Kpn I,
Pac I, Nhe I, Swa I, Sma I, Spe I and Not I sites. Modification of
the human CMV immediate early promoter was accomplished by
substituting the sequence between the Sac I and the second Not I
sites of pCMV-MC1 with a synthetic linker (shown below). The linker
contains a half site for Sac I following by Pac I, Spe I and a half
site for Not I. After annealing the two single stranded
oligonucletides, the linker was cloned into pCMV-MC1 between the
Sac I and Not I sites, and a selected clone was designated pCMV-S1.
The Spa I site of pCMV-S1 could not be cut, possibly due to a
mistake in the oligo sequence. Therefore, the fragment between Pac
I and Hind III in pCMV-S1 was replaced with Pac I (at position
877)-Hind III (at position 1162) fragment from pCMV-MC1. Thus, a
Spe I site was regained. This final construct (pCMV-S) was used to
clone the full length P129 genome.
[0156] Linker sequence (SEQ ID NO: 32, first below and SEQ ID NO:
33, second below):
TABLE-US-00003 5'CGTTAATTAAACCGACTAGTGC 3' 3'
TCGAGCAATTAATTTGGCTGATCACGCCGG 5' _______ PacI SpeI____ SacI
NotI
[0157] The sequence immediately upstream of the 5' end of the P129
genome was modified to contain proper spacing and a convenient
restriction enzyme site (Pac I). This was done by designing
appropriate PCR primers (SEQ ID NO:34 and SEQ ID NO:35) for
amplification from pT7P129. After digestion with Pac I and Aat II,
this PCR fragment was subcloned into the Pac I and Aat II sites of
pT7RG (FIG. 1). The resulting plasmid was designated
pT7RG-deltaT7.
[0158] The final construction was completed by subcloning the viral
sequences from pT7RG-deltaT7 at the Pac I and Nde I sites into
pT7P129, creating pT7P129-deltaT7. The full length P129 genome was
digested from pT7P129-deltaT7 at Pac I and Spa I and transferred
into pCMV-S at the Pac I and Spa I sites. This constructed was
named pCMV-S-P129.
[0159] The sequence of the region of modification between the CMV
promoter TATA box and the 5' end of the P129 sequence in
pCMV-S-P129 is shown in SEQ ID NO:36 and schematically presented
below:
TABLE-US-00004 TATATAAGCAGAGCTCGTTAATTAAACCGTC 5' TATA box SacI
PacI ATGACGTATAGGTGTTGGC Start of P129 3'
[0160] To test the use of the CMV promoter to initiate PRRS virus
infection in cells, pCMV-S-P129 plasmid DNA (0.5 or 1.0 .mu.g) was
transfected into MARC-145 cells by lipofection using
Lipofectamine.TM. (Life Technologies Inc.). PRRS virus specific
cytopathic effect was observed after transfection and the presence
of PRRS virus antigen was determined by the immunofluorescent
antibody test.
[0161] PRRS virus was generated efficiently from pCMV-S-P129, and
the progeny virus can be passaged on MARC-145 cells. This
demonstrates that a PRRS virus infection can be initiated directly
from a plasmid cDNA encoding a PRRS virus, without an in vitro
transcription step. Furthermore, pCMV-S-P129 generated a greater
amount of progeny virus compared to plasmids wherein the 3' end of
the pCMV promoter was not immediately in front of the start of the
sequence encoding the North American PRRS virus.
Example V
Deletion of ORF4 from the North American PRRS Virus: Preparation of
a Replication-Defective Vaccine Thereby
[0162] A portion of the gene for ORF4, which encodes a membrane
glycoprotein, was deleted from an infectious cDNA clone of the PRRS
virus of the present invention. The resulting recombinant modified
PRRS virus is expected to be replication-defective in pigs and to
induce an immune response to the other PRRS virus proteins without
the risks of clinical disease, spread to non-vaccinated animals, or
reversion to virulence associated with attenuated live
vaccines.
[0163] Deletion of ORF4 from an infectious clone was accomplished
as follows. Plasmid p2.sub.--7D-4 (see FIG. 1) was used as template
in PCR to amplify the 5' and 3' flanking regions upstream and
downstream of ORF4. The upstream flank forward primer was
5'-AGGTCGAC GGCGGCAATTGGTTTCACCTAGAGTGGCTGCGTCCCTTCT-3' (SEQ ID
NO:37). This primer binds to genome positions 13194-13241, near the
beginning of ORF4, and introduces a mutation at position 13225
which destroys the ATG start codon of ORF4 without altering the
overlapping amino acid sequence of ORF3. The upstream flank reverse
primer was 5'-TCTTAAGCATTGGCTGTGATGGTGATATAC-3' (SEQ ID NO:38).
This primer binds to genome positions 13455-13477 within the ORF4
coding region, downstream of ORF3, and introduces an AflII site.
For the downstream flanking region, the forward primer was 5'-CTTC
TTAAGTCCACGCGTTTTCTTCTTGCCTTTTCTATGCTTCT-3' (SEQ ID NO:39). This
primer binds to genome positions 13520-13545 in the middle of ORF4,
and introduces AflII and MluI sites for directional cloning of
foreign genes. The reverse primer was 5'-TGCCCGGTCCCTT GCCTCT3'
(SEQ ID NO:40). This primer binds to genome positions 14981-14999
in the ORF7 coding sequence. A three-way ligation was performed
using the SalI-AflII fragment of the upstream flank PCR product,
the AflII-BsfEII fragment of the downstream flank PCR product, and
the SalI-BstEII fragment from plasmid p2.sub.--7D-4. All fragments
were gel-purified following digestion. The resulting plasmid
p2.sub.--7D-4-delta4N has 42 bases of the central portion of ORF4
deleted and replaced with a 15 base artificial cloning site. The
cloning site contains two restriction sites (AflII and MluI) that
are absent from both the viral genome and the plasmid backbone.
These can be used to facilitate directional cloning of foreign
genes into the space previously occupied by ORF4. The cloning site
also contains a stop codon (TAA) that is in frame with ORF4 and
further assures that functional ORF4 protein is not produced.
[0164] It was found that a more extensive deletion of the ORF4
coding sequence can be made without interfering with expression of
the downstream ORF5 envelope gene. In this case a shorter
downstream flanking region was amplified by PCR using the same
template and reverse primer, and using forward primer
5'-GTTTACGCGTCGCTCCTTGGTGGTCG-3' (SEQ ID NO:41). This primer binds
to genome positions 138654-13669 near the 3' end of ORF4, and
contains an AflII site. Two-way ligation between the AflII-BstEII
fragment of the downstream flank PCR product and the AflII-BstEII
fragment from plasmid p2.sub.--7D-4-delta4N yielded the new plasmid
p2.sub.--7D-4-delta4NS. This plasmid has 176 bases of the ORF4
coding sequence deleted and replaced with the 15 base cloning
site.
[0165] The changes made in p2.sub.--7D-4-delta4N and
p2.sub.--7Ddelta4NS were incorporated into the full-length genomic
clone by replacing the BsrGI-SpeI fragment from pCMV-S-P129 with
the modified BsrGI-SpeI fragments from p2.sub.--7D-4-delta4N and
p2.sub.--7D-4-delta4NS. The resulting plasmids pCMV-S-P129delta4N
and pCMV-S-P129delta4NS were used to transfect cells.
[0166] In contrast to pCMV-S-P129, transfection of MARC-145 cells
with plasmids pCMV-S-P129delta4N or pCMV-S-P129delta4NS did not
result in viral plaques or fluorescent foci, Individual transfected
cells can be seen to be producing the ORF7 nucleocapsid protein,
suggesting that the ORF4 gene product is not required for RNA
replication or expression of viral genes, but is essential for
release of infectious progeny virus. Since deletion of ORF4 is
lethal to virus replication, it is necessary to provide this
protein. This can be accomplished by using a complementing cell
line. We created ORF4-expressing MARC-145 cell lines by stable
transfecting cells with a plasmid containing both ORF4 and the
neomycin resistance gene. After selection for neomycin resistance
using the antibiotic G418, single-cell colonies were expanded and
characterized. After transfection with pCMV-S-P129delta4NS, three
ORF4-expressing cell clones yielded live virus that can be
propagated in these cells but not in MARC-145 cells. One of these,
MARC400E9, was further characterized. Immunofluorescent staining
for viral nucleocapsid in MARC400E9 cells transfected with plasmid
pCMV-S-P129delta4NS was positive.
[0167] Virus derived by transfecting MARC400E9 cells with the
pCMV-S-P129delta4NS plasmid (designated P129delta4NS) was amplified
by passaging several times on MARC400E9 cells and was used to
vaccinate pigs against a virulent PRRSV challenge. Live virus was
formulated with one of three different types of adjuvant or used
without adjuvant, and was delivered in two doses by one of two
vaccination routes (intranasal followed by intramuscular, or
intramuscular followed by a second intramuscular dose).
[0168] At approximately three weeks (Day 0) and five weeks (Day 14)
of age, seroenegative conventional pigs were vaccinated according
to the Table 2, below. The pigs in Group J were considered sentinel
pigs and were necropsied approximately one week prior to challenge
to evaluate the health status of all pigs.
TABLE-US-00005 TABLE 2 Test groups selected for vaccination derived
from P129delta4NS Group Vaccine N Route* Adjuvant A P129delta4NS 10
IN/IM None B P129delta4NS 10 IM/IM None C P129delta4NS 10 IN/IM
rmLT** D P129delta4NS 10 IM/IM rmLT E P129delta4NS 10 IN/IM
QuilA/Cholesterol F P129delta4NS 10 IM/IM QuilA/Cholesterol G
P129delta4NS 10 IN/IM Amphigen H P129delta4NS 10 IM/IM Amphigen I
PBS only 10 IM/IM None J None 10 NA NA *IN--intranasal;
IM--intramuscular. **recombinant mutant heat-labile enterotoxin
from E. coli.
[0169] The first and second intramuscular vaccinations were
administered in the left and right sides of the neck, respectively,
On Days 0, 13, 21 and 28, blood samples were collected for serology
(IDEXX HerdChek PRRS ELISA). At approximately three weeks following
the second vaccination (Day 35), all pigs were challenged with 1 mL
of parental P129 virus instilled drop-wise in each nostril (a total
of 2 mL/pig or 1.2.times.10.sup.6 pfu), On Days 35, 38, 42 and 45,
blood samples were collected from all pigs for serology and for
PRRSV titration (by TCID50 assay). On Days 45 and 46, pigs were
euthanized and necropsied. Lungs were removed from the chest
cavity, examined for PRRS lesions, and photographed. Necropsies
were performed at the Animal Disease Research and Diagnostic
Laboratory (ADRDL) at South Dakota State University, Brookings, S.
Dak.
[0170] The serological results showed induction of anti-PRRSV
antibody in several of the vaccinated groups prior to challenge,
and priming of the humoral immune system for a rapid post-challenge
antibody response in all vaccinated groups. Immediately before
challenge (Day 35), the average S/P ratio (Sample/Positive control
ratio) value in the unvaccinated controls (group I) was 0.003. All
eight of the vaccinated groups had higher values, ranging from
0.005 (group B) up to 0.512 (group H). By one week after challenge
(Day 42), the control group was beginning to mount an antibody
response to the challenge virus (S/P value of 0.171). All eight
vaccinated groups had much higher antibody levels, ranging from
0.858 (group 8) to 1.191 (group G). This represents an increase in
anti-PRRSV antibodies of approximately 5- to 10-fold as a result of
priming of the humoral immune system.
TABLE-US-00006 TABLE 3 Anti-PRRSV antibody levels (S/P ratios) Day-
Day- Day- Day- Day- Day- Day- Day- 1 13 21 28 35 38 42 45 Group
None/IN 0.003 0.008 0.004 0.002 0.015 0.102 0.862 2.270 A Group
None/IM 0.005 0.015 0.024 0.022 0.005 0.105 0.858 2.053 B Group
rmLT/IN 0.002 0.030 0.015 0.021 0.016 0.108 1.219 2.653 C Group
rmLT/IM 0.002 0.042 0.143 0.149 0.138 0.229 1.271 2.679 D Group
QuilA/IN 0.015 0.039 0.084 0.048 0.013 0.097 1.217 2.299 E Group
QuilA/IM 0.001 0.020 0.104 0.115 0.085 0.109 1.240 2.593 F Group
Amph/IN 0.002 0.001 0.047 0.051 0.061 0.080 1.919 3.484 G Group
Amph/IM 0.022 0.006 0.460 0.531 0.512 0.492 1.601 3.371 H Group PBS
only 0.008 0.020 0.001 0.001 0.003 0.053 0.171 0.881 I
[0171] Following challenge with virulent PRRSV, serum viremia was
determined. At three days post challenge (Day 38) the titer of
virus in the unvaccinated control group had reached 2.58 logs. All
eight of the vaccinated groups showed reduced viremia, ranging from
2.52 (group E) down to 1.07 logs (group H). This represents more
than a 30-fold reduction in virus levels relative to the control
group, see Table 4.
TABLE-US-00007 TABLE 4 Serum viremia (log 10 TCID50 titers) on day
38 (three days post challenge) Group A None/IN 2.18 Group B None/IM
1.98 Group C rmLT/IN 2.15 Group D rmLT/IM 2.48 Group E QuilA/IN
2.52 Group F QuilA/IM 1.65 Group G Amph/IN 1.74 Group H Amph/IM
1.07 Group I PBS only 2.58
[0172] At necropsy, all pigs were examined for the presence of
macroscopic lung lesions resulting from the PRRS challenge virus.
In the unvaccinated control group, 90% of the animals showed lung
lesions. In contrast, all eight of the vaccinated groups showed
reduced levels of lung lesions (ranging from 80% in group D down to
22% in group A). Vaccination reduces damage to the lungs that
result from PRRSV infection. See Table 5.
TABLE-US-00008 TABLE 5 Number of pigs with macroscopic lung
lesions/total pigs (percent positive) Group A None/IN 2/9 (22%)
Group B None/IM 7/10 (70%) Group C rmLT/IN 6/10 (60%) Group D
rmLT/IM 8/10 (80%) Group E QuilA/IN 5/10 (50%) Group F QuilA/IM
4/10 (40%) Group G Amph/IN 7/10 (70%) Group H Amph/IM 5/9 (56%)
Group I PBS only 9/10 (90%)
[0173] The above swine data demonstrates the process of vaccinating
swine with the recombinant North American PRRS virion containing
the ORF 4 deletion. The results of the above data illustrate that
the P129delta4NS virus, which is deleted in ORF4, is useful as a
vaccine to protect pigs from disease caused by the PRRS virus.
Efficacy of the vaccine may be increased by formulation with
various adjuvants and by changing the route of administration.
Example VI
Use of Gene-Deleted PRRS Virus as a Vector for Expression of
Foreign Genes
[0174] In order to determine whether heterologous genes can be
expressed from a gene-deleted PRRS virus, we inserted a copy of
green fluorescent protein (GFP) into the site of ORF4 deletion in
plasmid pCMV-S-P129delta4N. The GFP gene was amplified from a
commercially available plasmid vector using PCR primers that
introduced an AflII site at the 5' end of the gene and an MluI site
at the 3' end of the gene. The resulting plasmid
pCMV-S-P129delta4N-GFP was used to transfect MARC-145 and MARC400E9
cells. As anticipated, MARC-145 cells did not support replication
of the ORF4-deleted virus. Single green cells resulting from
primary transfection were seen under the UV scope, indication that
GFP was being expressed, but the virus did not spread to
neighboring cells and no CPE was observed. In contrast, large green
foci were observed in transfected MARC400E9 cells. Visible plaques
formed and merged, destroying the monolayer. These results indicate
that foreign genes can be expressed from ORF4-deleted PRRS virus,
and that increasing the size of the viral genome by 692 bases
(4.5%) does not interfere with packaging of the viral RNA into
infectious particles.
Example VII
Use of Replication-Competent PRRS Virus as a Vector for Expression
of Foreign Genes
[0175] In order to determine whether heterologous genes can be
expressed from a replication-competent PRRS virus, we inserted a
copy of GFP into the region between ORF1b and ORF2. Since the
leader/junction (L/J) sequence for ORF2 lies within ORF1b, this L/J
sequence was used to drive expression of the GFP gene and a copy of
the ORF6 L/J sequence was inserted downstream from GFP to drive
expression of ORF2.
[0176] Plasmid p2.sub.--7D-4 (see FIG. 1) was used as template in
PCR to amplify the 5' and 3' flanking regions upstream and
downstream of the insertion site. The upstream flank forward primer
was 5'-AACAGAAGAGAGTGTCGGGTCCAC-3' (SEQ ID NO:42). This primer
binds to genome positions 11699-11721 in ORF1b. The upstream flank
reverse primer was 5'-GCTTT
GACGCGTCCCCACTTAAGTTCAATTCAGGCCTAAAGTTGGTTCA-3' (SEQ ID NO:43).
This primer binds to genome positions 12031-12055 in ORF1b and adds
AflII and MluI sites for directional cloning of foreign genes
between ORF1b and ORF2. The downstream flank forward primer was
5'-GCGACGCGTGTTCCGTGGCAACCCCTTTAACCAGAGTTTCAGCGG
AACAATGAAATGGGGTCTATACAAGCCTATACAAAGCCTCTTCGACA-3 (SEQ ID NO:44).
This primer binds to genome positions 12056-12089 in ORF2 and
contains an MluI site followed by the 40 bases that precede the
start of ORF6 (containing the ORF6 L/J sequence). The downstream
flank reverse primer was 5'-AACAGAACGGCACGATACACCACAAA-3' (SEQ ID
NO:45). This primer binds to genome positions 13819-13844 in ORF5.
A three-way ligation was performed using the Eco47III-MluI fragment
of the upstream flank PCR product, the MluI-BsrGI fragment from the
downstream flank PCR product, and the Eco47III-BsrGI fragment from
pCMV-S-P129. The resulting plasmid pCMV-S-P129-1bMCS2 contains the
entire P129 genome with a cloning site and an additional L/J site
between ORF1b and ORF2. The plasmid produces functionally normal
virus when transfected into MARC-145 cells.
[0177] The GFP gene from a commercially available plasmid was PCR
amplified using primers that add an AflII site to the 5' end and an
MluI site to the 3' end of the gene. After digestion of the PCR
fragment and PCMV-SP129-1bMCS2 with AflII and MluI, the insert was
ligated into the vector to yield plasmid pCMV-S-P129-bGFP2. This
plasmid produced green plaques when transfected into MARC-145
cells. The resulting virus can be passaged onto MARC-145 cells and
continued to produce green plaques when observed under the UV
scope. Thus, foreign genes may be expressed from
replication-competent PRRS virus vectors. The P129-1bGFP2 virus
contains a genome which is 774 bases (5%) longer than that of its
P129 parent, yet it is packaged normally.
Example VIII
Deletion of ORF 2 (Minor Structural Protein) from the North
American PRRS Virus; Preparation of a Replication-Defective
Vaccine
[0178] The following example illustrates the preparation of the
North American PRRS virions containing the ORF 2 deletion.
[0179] The viral minor structural protein encoded by ORF2 is
deleted from an infectious cDNA clone of the PRRS virus of the
present invention. The resulting recombinant modified PRRS virus is
replication-defective in pigs and can induce an immune response to
the other PRRS virus proteins without the risks of clinical
disease, spread to non-vaccinated animals, or reversion to
virulence associated with attenuated live vaccines.
[0180] Deletion of ORF2 from an infectious clone was accomplished
as follows. Plasmid p2.sub.--7D-4 (see FIG. 1) was used as template
in PCR to amplify the 5' and 3' flanking regions upstream and
downstream of ORF2. The upstream flank forward primer was
5'-CAAAGGGC GAAAAACCGTCTATCA-3' (SEQ ID NO:46), which binds within
the cloning vector. The upstream flank reverse primer was
5'-CCCCACTTAAGTTCAAGTTCAATTCAGGC-3' (SEQ ID NO:47), which binds to
genome positions 12045-12067 near the beginning of ORF2. The
downstream flank forward primer was
5'-GCTCCTTAAGAACAACGCGTCGCCATTGAAGCCGAGA-3' (SEQ ID NO:48), which
binds to genome positions 12492-12528. The downstream flank reverse
primer was 5'-GCAAGCCTTATAACGAAGCAAATC (SEQ ID NO:49), which binds
to genome positions 14131-14154. A 3-way ligation was performed,
using the XhoI-AflII fragment of the 5' flanking PCR product, the
AflII-BsrG1 fragment of the 3' flanking PCR product, and the large
XhoI-BsrGI fragment from plasmid p2.sub.--7D-4. All fragments were
gel purified following restriction enzyme digestion. The resulting
plasmid p2.sub.--7D4delta2 was deleted in the region of ORF2 that
does not overlap ORF3 or it's 5' transcriptional regulatory
sequences. Two restriction sites that are absent in both the viral
genome and the plasmid backbone, AflII and MluI, have been
introduced to facilitate directional cloning of foreign genes into
the space previously occupied by ORF2.
[0181] The changes made in p2.sub.--7D4delta2 were incorporated
into a full-length genomic clone by replacing the AfeI-BsrGI
fragment from pCMV-S-P129 with the modified sequence from
p2.sub.--7D4delta2. The resulting plasmid pCMV-S-P129delta2 was
used for transfections.
[0182] Since the deletion of ORF2 is lethal to virus replication,
it is necessary to provide this protein in trans to allow
generation of ORF2-deficient PRRS virus. This can be accomplished
by using a complementing cell line. We created ORF2-expressing
MARC-145 cell lines were created by stably transfecting cells with
a plasmid containing both the ORF2 gene from P129A and the neomycin
resistance gene. After selecting for neomycin resistance using the
antibiotic G418, single-cell colonies were expanded and
characterized. After transfecting with pCMV-S-P129delta2, three
cell clones yielded live viruses that can be propagated and passed
only in these ORF2-expressing cells. This virus was designated
P129delta2.
[0183] Recombinant virus P129delta2 was used to vaccinate groups of
20 sero-negative conventional pigs. At three weeks of age (Day 0)
and six weeks of age (Day 20), pigs were vaccinated according to
Table 6, below. Controls were mock vaccinated with phosphate
buffered saline (PBS). Amphigen adjuvant was not viricidal to the
live vaccine virus.
TABLE-US-00009 TABLE 6 Various groups of 20 sero-negative
conventional pigs vaccinated with P129delta2. Treatment Group
Route* Adjuvant Titer/Dose (log10 TCID.sub.50) P129delta2 IM IM/IM
5% Amphigen 5.8 P129delta2 IT IT/IT None 5.7 Mock vaccinated IT/IT
None NA (PBS) Controls *IM--intramuscular; IT--intratracheal.
[0184] At three weeks following second vaccination (Day 42, 9 weeks
of age), pigs were challenged with approximately 2.8 mL of virulent
P129 challenge virus (3.41.times.10.sup.5 TCID.sub.50/mL) in each
nostril, to achieve a total challenge volume of 5.6 mL
(1.91.times.10& TCID.sub.50). Pigs were bled periodically for
determination of anti-PRRSV antibody (IDEXX HerdChek PRRS ELISA)
and serum viremia (TCID.sub.50 assay).
TABLE-US-00010 TABLE 7 Anti-PRRSV antibody levels (S/P ratios) Day
Day Day Day Day Day Day Day 2 19 28 34 42 52 55 63 P129delta2 IM
0.026 0.132 1.265 1.319 1.389 1.995 2.322 2.02 P129delta2 IT 0.011
0.004 0.026 0.115 0.036 1.306 1.584 1.501 Mock vaccinated (PBS)
Controls 0.001 0.002 0.071 0.003 0.004 0.763 1.362 1.395
[0185] Two vaccinations with live Amphigen-adjuvanted P129delta2
intramuscularly resulted in a marked increase in anti-PRRSV
antibody in the serum prior to challenge, as well as an anamnestic
response following challenge. Two intratracheal vaccinations with
unadjuvanted P129delta2 were less effective, but nevertheless
resulted in a slight increase in antibody level prior to challenge
and a more rapid response following challenge, relative to the
mock-vaccinated control group.
TABLE-US-00011 TABLE 8 Results from two vaccinations with live
Amphigen-adjuvanted P129delta2 and control. Serum titer (log 10
TCID.sub.50) and number of positive pigs following PRRSV challenge
Days post-challenge Treatment 0 5 8 10 14 21 P129delta2 Titer 0.0
1.5 0.3 0.0 0.0 0.0 IM Positive/ 0/19 13/18 4/18 1/18 0/8 0/8 Total
(%) (0%) (72%) (22%) (6%) (0%) (0%) P129delta2 Titer 0.0 2.3 2.1
1.5 0.5 0.2 IT Positive/ 0/20 19/20 19/20 17/20 4/10 1/10 Total (%)
(0%) (95%) (95%) (85%) (40%) (10%) Mock Titer 0.0 2.4 2.0 1.4 0.3
0.0 vaccinated (PBS) Controls Positive/ 0/20 19/19 19/19 16/19 3/9
0/9 Total (%) (0%) (100%) (100%) (84%) (33%) (0%)
[0186] Intramuscular vaccination with two doses of live
Amphigen-adjuvanted P129delta2 virus resulted in a reduction of the
number of viremic pigs (from 100% to 72%), reduction in the
duration of viremia (from about 21 days to about 14 days), and
reduction in the average serum virus load of nearly one log at 5
days post-infection (the peak of viremia) and more than one log at
later times. Intratracheal vaccination with unadjuvanted P129delta2
showed little or no reduction in viremia relative to the
mock-vaccinated control group.
Example IX
Insertion of Unique MluI and SgrAI Restriction Sites into the PRRS
Virus Genome within Nsp2
[0187] The QuikChange.RTM. II XL Site-Directed Mutagenesis kit
(Stratagene; La Jolla, Calif.) was used to introduce a unique MluI
restriction enzyme site into the PRRS virus genome at nucleotide
position 3,219 using plasmid pCMV-S-P129 as template. Genome
position 3,219 lies within the nonstructural protein 2 (nsp2)
coding region, which is part of ORF1a (FIG. 5). This site is
located within the hypervariable C-terminal portion of nsp2. The
sequence of the parental virus beginning at genome position 3,219
(ACACGC) is such that changing only two nucleotides (ACGCGT) allows
the introduction of an MluI site without altering the encoded amino
acid sequence. The mutagenic primers used to insert the MluI site
(MluI F and MluI R) are shown in Table 1. QuikChange II XL
reactions were as recommended by the manufacturer and contained 150
picomoles of each primer and 10 ng of plasmid DNA as template.
Reaction conditions were as follows: initial denaturation at
95.degree. C. for 60 seconds, 18 cycles of 95.degree. C.
denaturation for 50 seconds, 60.degree. C. annealing for 50
seconds, and 68.degree. C. extension for 20 minutes, concluding
with a 7 minute incubation at 68.degree. C. Successful introduction
of the new site was determined based on the ability of the
resulting plasmid to be cut with MluI and confirmed by DNA
sequencing. The new plasmid was named pCMV-S-P129-Nsp2-MluI, and
was used as a backbone for the insertion foreign DNA fragments.
[0188] A unique SgrAI restriction enzyme site was inserted into
plasmid pCMV-S-P129-Nsp2-Mlu as follows. A 4500 bp PCR product
(genome positions 3201-7700) was amplified using template
pCMV-S-P129-Nsp2-Mlu, primers Mlu-F and 7700-R (Table 1), and
ExTaq.TM. polymerase (TakaRa Mirus Bio; Madison, Wis.) according to
the manufacturers directions. The forward primer Mlu-F contains the
unique MIul site added in the previous step, and the reverse primer
7700-R contains a unique PmeI site to be used in a subsequent
cloning step. Reactions conditions were: initial denaturation at
95.degree. C. for 120 seconds, 30 cycles of 94.degree. C.
denaturation for 35 seconds, 58.degree. C. annealing for 35
seconds, and 72.degree. C. extension for 4.5 minutes. The resulting
PCR product was cloned the TOPO PCR XL cloning kit (Invitrogen
Corp.; Carlsbad, Calif.). The QuikChange II XL Site-Directed
Mutagenesis Kit was used to introduce a unique SgrAI site beginning
at genome position 3614 according to the manufacturers directions.
The original sequence TACCGGTG was changed to CACCGGTG without
altering the encoded amino acid sequence, using primers SgrAI-F and
SgrAI-R (Table 1). Reactions conditions were: initial denaturation
at 95.degree. C. for 60 seconds, 18 cycles of 95.degree. C.
denaturation for 50 seconds, 60.degree. C. annealing for 50
seconds, and 68.degree. C. extension for 9 minutes, followed by a
68.degree. C. polishing reaction for 7 minutes. After
transformation, plasmids containing the new SgrAI site were
selected by restriction digestion and sequence analysis. The 4,456
bp MluI-PmeI fragment from this plasmid was ligated to the 14,436
bp MluI-PmeI fragment of PCMV-S-P129-Nsp2-Mlu to yield
pCMV-S-P129-Nsp2-Mlu/SgrA. This plasmid was transfected into
MARC-145 cells using Lipofectamine 2000 (Invitrogen Corp.;
Carlsbad, Calif.) according to the manufacturer's instructions.
Three days post-transfection lysates were titrated by limiting
dilution. Infectious virus was recovered from plasmid
pCMV-S-P129-Nsp2-Mlu/SgrA at levels that were similar to plasmids
pCMV-S-P129 and pCMV-S-P129-Nsp2-MIu.
Example X
Insertion of Green Fluorescent Protein (GFP) into Nsp2
[0189] MluI sites were placed on the 5' and 3' ends of GFP,
amplified by PCR from plasmid pEGFP-C3 (Clontech, Mountain View,
Calif.), using gene-specific PCR primers GFP-Mlu-F and GFP-Mlu-R
(Table 1). ExTaq.TM. polymerase (TakaRa Mirus Bio; Madison, Wis.)
was used according to the manufacturer's recommendation. Reactions
conditions were: initial denaturation at 95.degree. C. for 120
seconds, 30 cycles of 94.degree. C. denaturation for 35 seconds,
56.degree. C. annealing for 35 seconds, and 72.degree. C. extension
for 60 seconds. The PCR product was digested with MluI and ligated
into MIul-digested pCMV-S-P129-Nsp2-Mlu. DNA sequencing confirmed
that GFP had been inserted in-frame, in the forward orientation,
into nsp2. The new plasmid was designated
pCMV-S-P129-Nsp2-Mlu-GFP.
[0190] Plasmids pCMV-S-P129, pCMV-S-P129-Nsp2-Mlu, and
pCMV-S-P129-Nsp2-Mlu-GFP were transfected into the MARC-145 monkey
kidney cell line in order to generate infectious virus. Cell lines
were maintained at 37.degree. C., 5% CO.sub.2 in modified Eagle's
medium (MEM) supplemented with 8% fetal bovine serum, 0.008%
Fungizone and 0.01% penicillin/streptomycin. Approximately one day
prior to transfection, 2.times.10.sup.5 cells/well were seeded into
a 12-well plate. Transfection of infectious cDNA clones was
performed using Lipofectamine 2000 (Invitrogen, Carlsbad, Calif.)
according to the manufacturer's instructions. At 4 days
post-transfection, virus was harvested by subjecting the infected
cells to three freeze-thaw cycles. Cell debris was removed by
centrifugation at 1000.times.g for 10 minutes, and virus-containing
culture supernatants collected. Recombinant viruses rescued from
plasmids pCMV-S-P129, pCMV-S-P129-Nsp2-Mlu, and
pCMV-S-P129-Nsp2-Mlu-GFP were designated P129, P129-Nsp2-Mlu, and
P129-Nsp2-Mlu-GFP, respectively.
[0191] To determine virus titer, end-point dilutions were performed
on MARC-145 cells in 96 well plates. Titrations were performed in
triplicate and results presented as TCID.sub.50/ml. Cells were
fixed at 3 days post-transfection and immunostained either directly
with the nucleocapsid-specific monoclonal antibody SDOW-17
conjugated to FITC, or indirectly with the nucleocapsid-specific
primary monoclonal antibodies SR30 or JP24 followed by Alexaflour
594-conjugated goat anti-mouse IgG secondary antibody (Molecular
Probes/Invitrogen Corp.; Carlsbad, Calif.). Titers of P129 and
P129-Nsp2-Mlu were similar, while the titer of P129-Nsp2-Mlu-GFP
was slightly lower. The P129-Nsp2-Mlu-GFP virus expressed GFP and
formed fluorescent green foci. Within the focus of infection, cells
with perinuclear green fluorescence are seen, due to expression of
the Nsp2-GFP fusion peptide.
[0192] For western blot analysis, cells were lysed with 100 ul of
2.times. Laemmli sample buffer and boiled for 10 min. Proteins were
fractionated on SDS-polyacrylamide gels (Bio-Rad; Hercules, Calif.)
under reducing conditions. Proteins were transferred onto
nitrocellulose membranes and processed at room temperature.
Membranes were blocked for 1 hr with 5% nonfat dry milk in washing
solution (0.2% Tween 20 in PBS). Affinity purified goat anti-GFP
antibody (Rockland Immunochemicals Inc., Gilbertsville, Pa.) was
diluted 1:1000 in blocking buffer and incubated with membranes for
1 hr. Membranes were washed three times for 15 minutes with
TBS-Tween. Rabbit anti-goat horseradish peroxidase-conjugated
antibody (Rockland) was diluted 1:1000 in blocking buffer and
incubated with membranes for 1 hr. Membranes were washed three
times for 15 minutes with TBS-Tween. Peroxidase activity was
detected using the Supersignal West Pico Chemiluminescent substrate
(Pierce Chemical Company; Rockford, Ill.). Western blots identified
a 70 kDa peptide from P129-Nsp2-Mlu-GFP infected cells that reacted
with anti-GFP antibody. Using a similar procedure, the GFP gene was
also inserted into nsp2 at the SgrAI site in the plasmid
pCMV-S-P129-Nsp2-Mlu/SgrA. Primers GFP-SgrA-F and GFP-SgrA-R (Table
1) were used to add SgrAI sites to the ends of the GFP gene, using
plasmid pEGFP-C3 as template. ExTaq.TM. polymerase (TakaRa Mirus
Bin; Madison, Wis.) was used according to the manufacturer's
recommendation. Reactions conditions were: initial denaturation at
95.degree. C. for 120 seconds, 30 cycles of 94.degree. C.
denaturation for 35 seconds, 55.degree. C. annealing for 35
seconds, and 72.degree. C. extension for 35 seconds. The PCR
product was digested with SgrAI and ligated into SgrAI-digested
pCMV-S-P129-Nsp2-Mlu/SgrA. DNA sequencing confirmed that GFP had
been inserted in-frame, in the forward orientation, into nsp2. The
new plasmid was designated pCMV-S-P29-Nsp2-SgrA-GFP. This plasmid
produced infectious virus and fluorescent green foci when
transfected into MARC-145 cells.
TABLE-US-00012 TABLE 9 PCR primers used to introduce the
heterologous genes. Primer SEQ (genome ID position) Sequence
Orientation NO MluI-F CTGTCAAGTGTTAGGATCACG Forward 50 (3201-3242)
CGTCCAAAATACTCAGCTCAA MluI-R TTGAGCTGAGTATTTTGGACG Reverse 51
(3201-3242) CGTGATCCTAACACTTGACAG GFP-Mlu-F GCCACGCGTGCCACCATGGTG
Forward 52 AGCAAGGGCGAG GFP-Mlu-R GCCACGCGTGTTATCTAGATC Reverse 53
CGGTGGATCC 7700-R TCAAGCCGCTGGCGGCTAGCA Reverse 54 (7661-7700)
GTTTAAACACTGCTCCTTA SgrAI-F CTCGGGAAAATAGAAAACACC Forward 55
(3597-3637) GGTGAGATGATCAACCAGGG SgrAI-R CCCTGGTTGATCATCTCACCG
Reverse 56 (3597-3637) GTGTTTTCTATTTTCCCGAG GFP-SgrA-F
GCCGCCCACCGGTGAGGTGAG Forward 57 CAAGGGCGAGGAGCTGTTC GFP-SgrA-R
GCCGCCCACCGGTGTTGTTAT Reverse 58 CTAGATCCGGTGGATC All sequences are
5' to 3'. Restriction sites are underlined. Nucleotide positions
are based on the sequence of PRRSV strain P129.
Example XI
Construction of PRRS Viruses Having a Deleted Portion of Nsp2
[0193] The previously made plasmid pCMV-S-P129-Mlu/SgrA (see
Example IX) was used as the backbone plasmid for construction of
recombinant PRRS viruses lacking a 132 amino acid region of nsp2,
and with either green fluorescent protein (GFP) or the influenza
hemagglutinin (HA) tag inserted into the deleted region.
[0194] The enhanced GFP gene from a commercially available plasmid
(pEGFP-C3, Clontech) was PCR amplified using primers that add MluI
and SgrAI restriction enzyme recognition sites to the 5' and 3'
ends, respectively. The forward primer was GFP-MLU-F2
TABLE-US-00013 SEQ ID NO. 59 (5'-GCCACGCGTGTGAGCAAGGGCGAGGAGCTG-3')
and the reverse primer was GFP-SgrA-R SEQ ID NO. 58
(5'-GCCCACCGGTGTTGTTATCTAGATCCGGTGGATC-3').
PCR reactions used ExTaq polymerase (TakaRa Mirus Bio, Madison,
Wis.) according to the manufacturer's instructions. Reaction
conditions included an initial 120 second denaturation at 95 C.,
followed by 30 cycles of denaturation at 94 C. for 35 seconds,
annealing at 55 C. for 35 seconds, and extension at 72 C. for 35
seconds. After digestion of the PCR fragment and of
pCMV-S-P129-Mlu/SgrA with MluI and SgrAI, the insert was ligated
into the vector to yield plasmid pCMV-S-P129-Mlu-GFP-SgrA. Deletion
of the 132 amino acid region and insertion of GFP (257 amino acids)
was confirmed by DNA sequencing. This plasmid produced viable
virus, which in turn produced green fluorescent foci of infection
when transfected into MARC-145 cells and observed under a
fluorescence microscope. This virus was designated
P129-Mlu-GFP-SgrA.
[0195] The HA tag is a small peptide epitope (YPYDVPDYA), derived
from the influenza virus hemagglutinin gene, that reacts with
commercially available monoclonal antibodies. A synthetic adapter
was created by heating and slowly annealing two phosphorylated
oligonucleotides, designated "HA tag F"
(5'-CGCGCGTATACCCATACGACGTCCCAGACTACGCA-3') SEQ ID NO. 60 and "HA
tag R" (5'-CCGGTGCGTAGTCTGGGACGTCGTATGGGTATA-3') SEQ ID NO. 681.
This adapter, with MluI and SgrAI half-sites, was then ligating
into pCMV-S-P129-Mlu/SgrA which was previously digested with MluI
and SgrAI. The structure of the resulting plasmid,
pCMV-S-P129-Mlu-HA-SgrA, was confirmed by DNA sequencing. An
in-frame fusion of the HA tag peptide 9-mer replaces the 132 amino
acid deletion in nsp2. The plasmid produced viable virus when
transfected into MARC-145 cells. This virus was designated
P129-Mlu-HA-SgrA.
[0196] In a separate experiment, a simple deletion of the same
region (without a simultaneous insertion) was engineered into a
different infectious cDNA clone, using a different methodology. The
plasmid pCMV-S-P129-PK contains a full-length infectious cDNA clone
of the P129 isolate of PRRS virus that was isolated from the serum
of an infected pig on primary porcine alveolar macrophage cells,
and subsequently passaged 16 times on the porcine kidney cell line
PK.9. The PK.9 cell line expresses the CD163 PRRS virus receptor,
and is fully permissive to PRRSV infection. A precise deletion of
396 nucleotides, which encodes the 132 amino acid region described
above, was generated in pCMV-S-P129-PK using the QuikChange II XL
Site-Directed Mutagenesis kit (Stratagene; La Jolla, Calif.) and
mutagenic primers P129-PK-3199F
(5'-CCCTGGAATTTAAGATCACAGGTGAGATGATCAACC-3) SEQ ID NO. 62 and
P129-PK-3637R (5'-CCCTGGTTGATCATCTCACCTGTGATCTTAACACTTGACAG-3') SEQ
ID NO. 63. The resulting plasmid pCMV-S-P129-PK-dnsp2 contained a
deletion of nsp2 amino acids 628-759 (confirmed by sequencing), and
produced viable progeny virus when transfected into PK.9 cells.
This virus was designated P129-PK-dnsp2.
Example XII
Development of an ELISA for the Detection of Serum Antibodies to a
132-Amino Acid Portion of Nsp2
[0197] The 132 amino acid portion of nsp2 that is deleted in
viruses P129-Mlu-GFP-SgrA and P129-Mlu-HA-SgrA is designated
P129-nsp2 (628-759). This peptide,
RPKYSAQAIIDLGGPCSGHLQREKEACLRMREACDAAKLSDPATQEWLSRMWDRVDMLTW
RNTSAYQAFRTLDGRFGFLPKMILETPPPYPCGFVMLPHTPAPSVSAESDLTIGSVATEDIPRI
LGKIENT) (SEQ ID NO. 64) was expressed as a recombinant peptide in
Escherichia coli, using the pHUE system (Catanzariti A M, Soboleva
T A, Jans D A, Board P G, Baker R T. 2004. An efficient system for
high-level expression and easy purification of authentic
recombinant proteins. Protein Sci. 13:1331-1339). In this
expression system, the peptide of interest is cloned and expressed
as a histidine-tagged/ubiquitin/PRRS peptide fusion (25 kDa
apparent molecular weight on SOS-PAGE). After an initial round of
purification by nickel ion affinity chromatography, the
histidine-tagged/ubiquitin/PRRS peptide is optionally incubated
with histidine-tagged/deubiquinating enzyme to cleave
histidine-tagged/ubiquitin from the PRRS peptide, in a second round
of nickel ion affinity chromatography, the
histidine-tagged/ubiquitin and the histidine-tagged/deubiquinating
enzyme are retained on the nickel ion affinity column and the free
PRRS peptide is eluted.
[0198] The ubiquitin-conjugated P129-nsp2 (628-759) peptide from
the first nickel affinity chromatography step was coated on ELISA
plates (0.1 ug/ml). Plates were blocked with 10% goat serum.
Dilutions of sera from infected and non-infected pigs were made in
PBS with 10% goat serum, and added to the blocked plates. After
incubation and washing, bound porcine antibodies were detected
using biotin-labeled goat anti-swine antibody, followed by
avidin-peroxidase. Peroxidase activity was detected using a
chromagenic substrate.
[0199] Serum from an uninfected control pig was serially diluted
from 1:10 to 1:20,480 and applied to the ELISA plates for analysis.
Optical density (OD) was below 0.4 in all cases. In contrast, serum
from a pig that had previously been infected with the heterologous
PRRS virus isolate VR2332 about 200 days earlier reacted in a
dilution-dependent manner, giving OD values in excess of 1.2 at
1:10 and 1:20 dilutions, and dropping below an OD of 0.4 only after
reaching a 1:640 dilution. The VR2332 virus is quite divergent from
the P129 isolate, and the 132 amino acid nsp2 (628-759) peptide
from VR2332
(RPKYSAQAIIDSGGPCSGHLEVKETCLSVMREACDATKLDDPATQEWLSRMWDRVDMLT
WRNTSVYQAICTLDGRLKFLPKMILETPPPYPCEFVMMPHTPAPSVGAESDLTIGSVATEDVP
RILEKIENV) (SEQ. ID NO. 65) shares only 85.6% identity with its
homolog that was used in the ELISA assay. This suggests that
antigenic epitopes are shared, and that an ELISA of this sort is
likely to be robust enough to detect infection with most, if not
all, type II ("North American" genotype) PRRS viruses. In addition,
the ELISA is sensitive enough to show a strong positive reaction
with serum from a pig whose antibody levels have been waning for a
long period of time (200 days post infection).
[0200] Pigs vaccinated with a virus that lacks the nsp2 (628-759)
peptide, due to genetic deletion, are not expected to induce
antibodies to this region. It is this ability to differentiate
vaccinated and naive (negative) pigs from pigs that have been
exposed to field strains of the PRRS virus (positive) that form the
basis of the utility of this invention. Pigs that test positive can
be removed from the herd or placed in isolation, thus aiding in the
management and possible eradication of the PRRS virus.
[0201] Alternatively to the peptides disclosed above, peptides
representing the corresponding region from other PRRS viruses can
be employed in a diagnostic assay. Numerous examples of such
peptides are provided for by the sequences disclosed in SEQ ID. NOs
66-15. That is 50 examples of similarly suitable peptides are
provided by the polypeptides disclosed in SEQ ID. NOs 66-115 In
addition to those examples, fragments of any of the peptides
described can be used as a reagent. Fragments can be as short as
ten amino acids, capable of forming and being recognized as an
epitope by an antibody molecule, or as long as the entire region.
For example, the peptide can comprise amino acids 1-10 of the
respective 132 amino acid nsp2 peptide. The peptide can comprise
amino acids 2-11 of the peptide. The peptide can comprise amino
acids 3-12 of the peptide. Peptides are selected in this fashion by
progressively "walking" down the amino acid sequence of the nsp2
fragment, all of the way through to amino acid 132, generating 123
possible 10-mer peptides.
[0202] In addition to 10-mer peptides, the fragment can be 11 amino
acid residues in length. Beginning with a fragment comprising amino
acid 1-11, and progressing to the C-terminal residue. 122 different
peptides are possible for the corresponding 132 amino acid region
in nsp2. Similarly, the fragment can be 12, 13, 14, 15, 16, 17, 18,
19, 20 or more residues in length, up to 131 residues in length,
and such peptides are readily identifiable by beginning at residue
1 and "walking" down the amino acid sequence of the corresponding
peptide. There are 7626 such fragments in a peptide of 132 amino
acid residues (including the full length peptide). Such a strategy
can be applied to the corresponding nsp2 sequence from any strain
of PRRS virus, making it possible to have a diagnostic kit specific
for that and possibly other related strains of PRRS virus.
Example XIII
Infection of Pigs with Recombinant Viruses
[0203] To establish the level of attenuation achieved by the
deletion of the nsp2 (628-759) peptide, and to evaluate the ability
of the deletion to serve as a serological marker, young pigs are
infected with the undeleted parental virus P129-Mlu/SgrA,
P129-Mlu-GFP-SgrA or P129-Mlu-HA-SgrA. Three groups of 10
conventional weaned pigs, 3 weeks of age, are housed separately. A
mock-infected group (6 pigs) is included in the study, and naive
pigs (contact controls, 2 per vaccine group) are commingled with
infected pigs in order to evaluate the ability of the viruses to
spread. After a week of acclimation, at about 4 weeks of age, pigs
are infected with the three viruses, or mock infected, by
delivering 2 ml of a diluted virus stock (at 1.times.10.sup.4
TCID.sub.50/ml) intramuscularly and 1 ml intranasally to each
nostril (total dose is 4.times.10.sup.4 TCID.sub.50/ml). Pigs are
monitored daily for clinical signs of disease from day -3 to day 10
(general condition, depression, loss of appetite, sneezing,
coughing, and respiratory distress), and rectal temperatures are
taken on day -1, 3, 7, and 10. On day 10, half of the pigs in each
group (selected by prior allotment) are necropsied in order to
examine lung lesions and to sample tissues for virus isolation and
histopathology. The remaining pigs are necropsied on day 28. All
pigs are weighed on arrival, on day -1 or 0, and at necropsy (day
10 or 28).
[0204] Blood (10 ml) is collected from all pigs on days -1 or 0, 3,
7, 10, 14, 21, and 28, into serum separator tubes. Sera are frozen
at -80 C. until used for the determination of anti-PRRSV antibodies
(by IDEXX HerdChek ELISA), neutralizing antibodies (by serum
neutralization assay), and virus isolation (titration of virus
infectivity by TCID.sub.50 assay). In addition, sera will be
assayed for antibodies against the nsp2 (628-759) peptide using the
ELISA described in Example XII above. Also, the induction of serum
antibodies to GFP or to the HA tag can be determined using
commercial kits or reagents.
[0205] The viruses with nsp2 (628-759) deleted are attenuated (less
virulent) relative to the parental virus P129-Mlu/SgrA, as
evidenced by a combination of one or more of the following
characteristics in infected pigs: (1) reduced clinical signs, (2)
reduced fever, (3) increased weight gain, (4) reduced number or
severity of lung lesions, (5) increased neutralizing antibody
levels, (6) decreased level or duration of viremia in serum, lung,
and/or tonsil tissue, or (7) reduced spread to naive contact
control pigs. Attenuated viruses with these characteristics are
useful as live vaccines.
[0206] All infected pigs test positive for anti-PRRSV antibodies
using a commercial ELISA (IDEXX HerdChek), with seroconversion
occurring no later than 21 days post-infection. Only those pigs
infected with undeleted parental virus P129-Mlu/SgrA are expected
to have antibodies specific to the nsp2 (628-759) peptide, as
measured using the ELISA described in Example XII. Such a vaccine
virus is useful for differentiating infected from vaccinated
animals (DIVA), otherwise known as a negatively marked vaccine.
[0207] Sera from pigs infected with P129-Mlu-GFP-SgrA or
P129-Mlu-HA-SgrA are assayed for antibodies to GFP and the HA tag,
respectively, by detecting these antibodies using commercially
available reagents and kits. Such positive serological markers or
"compliance markers", when incorporated into a vaccine, are useful
for determining which pigs in a herd have been successfully
immunized with the vaccine. In addition, the waning of antibodies
against the marker can be used as surrogate for the waning of
antibodies against the PRRS virus, giving an indication of when to
revaccinate.
[0208] In a separate pig study, the ability of an nsp2
(628-759)-deleted PRRS virus to function as a vaccine is tested
directly. The P129-PK-dnsp2 virus (Example XI) is used to immunize
4 week old pigs by delivering 2 ml of virus at 2.times.10.sup.4
TCID.sub.50/ml intramuscularly. After 28 days, these pigs are
challenged by infection with a virulent PRRS isolate (NADC20). The
severity of the disease induced by the NADC20 virus is compared to
disease induced in non-vaccinated (naive) pigs. A useful vaccine
will result in at least partial reduction of disease caused by
NADC20, including clinical signs, fever, reduced weight gain, lung
lesions, persistent viremia, and spread to contact control
pigs.
DEPOSIT OF BIOLOGICAL MATERIALS
[0209] The following biological material was deposited with the
American Type Culture Collection (ATCC) at 10801 University Blvd.,
Manassas, Va., 20110-2209, USA, on Nov. 19, 1998 and were assigned
the following accession numbers:
TABLE-US-00014 Plasmid Accession No. pT7P129A 203488 pCMV-S-P129
203489
[0210] All patents, patent applications, and publications cited
above are incorporated herein by reference in their entirety.
[0211] The present invention is not to be limited in scope by the
specific embodiments described herein, which are intended as single
illustrations of individual aspects of the invention, and
functionally equivalent methods and components are within the scope
of the invention. Indeed, various modifications of the invention,
in addition to those shown and described herein will become
apparent to those skilled in the art from the foregoing description
and accompanying drawings. Such modifications are intended to fall
within the scope of the appended claims.
Sequence CWU 1
1
115115450DNAPorcine reproductive and respiratory syndrome virus
1atgacgtata ggtgttggct ctatgccacg gcatttgtat tgtcaggagc tgtgaccatt
60ggcacagccc aaaacttgct gcacggaaaa cgcccttctg tgacagcctt cttcagggga
120gcttaggggt ctgtccctag caccttgctt ctggagttgc actgctttac
ggtctctcca 180cccctttaac catgtctggg atacttgatc ggtgcacgtg
cacccccaat gccagggtgt 240ttatggcgga gggccaagtc tactgcacac
gatgtctcag tgcacggtct ctccttcctc 300tgaatctcca agttcctgag
cttggggtgc tgggcctatt ttataggccc gaagagccac 360tccggtggac
gttgccacgt gcattcccca ctgtcgagtg ctcccccgcc ggggcctgct
420ggctttctgc gatctttcca attgcacgaa tgaccagtgg aaacctgaac
tttcaacaaa 480gaatggtgcg ggttgcagct gagatttaca gagccggcca
actcacccct gcagttttga 540aggctctaca agtttatgaa cggggttgtc
gctggtaccc cattgtcgga cctgtccctg 600gagtggccgt tcacgccaac
tccctacatg tgagtgacaa acctttcccg ggagcaactc 660atgtgttaac
caacctaccg ctcccgcaga ggcccaagcc tgaagacttt tgcccttttg
720agtgtgctat ggctgacgtc tatgacatta gccatgacgc cgtcatgtat
gtggccagag 780ggaaagtctc ctgggcccct cgtggcgggg atgaagtgaa
atttgaaacc gtccccgaag 840agttgaagtt gattgcgaac cgactccaca
tctccttccc gccccaccac gcagtggaca 900tgtctgagtt tgccttcata
gcccctggga gtggtgtctc cttgcgggtc gagcaccaac 960acggttgcct
tcccgctgat actgtccctg aagggaactg ctggtggtgc ttgtttgact
1020tgctcccacc ggaagttcag aataaagaaa ttcgccgtgc taaccaattt
ggctatcaaa 1080ccaagcatgg tgtccctggc aagtacctac agcggaggct
gcaagttaat ggtctccgag 1140cagtgactga tacagatgga cctattgtcg
tacagtactt ctctgttagg gagagttgga 1200tccgccactt cagactggcg
gaagaaccta gcctccctgg gtttgaagac ctcctcagaa 1260taagggtaga
gcctaatacg tcgccattgg gtggcaaggg tgaaaaaatc ttccggtttg
1320gcagtcacaa gtggtacggt gctggaaaga gagcaaggag agcacgctct
ggtgcaactg 1380ccacggtcgc tcactgcgct ttgcccgctc gcgaagccca
gcaggccaag aagctcgagg 1440ttgccagcgc caacagggct gagcatctca
agtactattc cccgcctgcc gacgggaact 1500gtggttggca ctgcatttcc
gccattacca accggatggt gaattccaaa tttgaaacca 1560ctcttcccga
gagagtgaga ccttcagatg actgggctac tgacgaggat cttgtgaata
1620ccatccaaat cctcaggctc cccgcggcct tggacaggaa cggtgcttgt
gctggcgcca 1680agtacgtgct caagctggaa ggtgagcact ggaccgtctc
tgtgacccct gggatgaccc 1740cttctttgct cccccttgaa tgtgttcagg
gttgttgtga gcataagagc ggtcttggtt 1800tcccagacgt ggtcgaagtt
tccggatttg accctgcctg tcttgaccga cttgctgaga 1860taatgcactt
acctagcagt gtcatcccag ctgctctggc cgagatgtcc gacgacttca
1920atcgtctggc ttccccggcc gccactgtgt ggactgtttc gcaattcttt
gcccgccaca 1980gaggaggaga gcatcctgac caggtgtgct tagggaaaat
tatcaacctt tgtcaggtga 2040ttgaggaatg ctgctgttcc cggaacaaag
ccaaccgggc taccccggaa gaggttgcgg 2100caaaagttga ccagtacctc
cgtggtgcag caagccttgg agaatgcttg gccaagcttg 2160agagggctcg
cccgccgagc gcgatggaca cctcctttga ttggaatgtt gtgcttcctg
2220gggttgagac ggcggatcag acaaccaaac agctccatgt caaccagtgc
cgcgctctgg 2280ttcctgtcgt gactcaagag cctttggaca gagactcggt
ccctctgacc gccttctcgc 2340tgtccaattg ctactaccct gcacaaggtg
acgaggtccg tcaccgtgag aggctaaact 2400ccgtgctctc taagttggag
ggggttgttc gtgaggaata tgggctcacg ccaactggac 2460ctggcccgcg
acccgcactg ccgaacgggc tcgacgagct taaagaccag atggaggagg
2520atctgctgaa attagtcaac gcccaggcaa cttcagaaat gatggcctgg
gcagccgagc 2580aggttgatct aaaagcttgg gtcaaaaatt acccacggtg
gacaccgcca ccccctccac 2640caagagttca gcctcgaaaa acgaagtctg
tcaagagctt gctagagaac aagcctgtcc 2700ctgctccgcg caggaaggtc
agatctgatt atggcagccc gattttgatg ggcgacaatg 2760ttcctaacgg
ttgggaagat tcgactgttg gtggtcccct tgacctttcg gcaccatccg
2820agccgatgac acctctgagt gagcctgtac ttatttccag gccagtgaca
tctttgagtg 2880tgccggcccc agttcctgca ccgcgtagag ctgtgtctcg
accgatgacg ccctcgagtg 2940agccaatttt tgtgtctgca ctgcgacaca
aatttcagca ggtggaaaaa gcaaatctgg 3000cggcagcagc gccgatgtac
caggacgaac ccttagattt gtctgcatcc tcacagactg 3060aatatggggc
ttctccccta acaccaccgc agaacgtggg cattctggag gtaagggggc
3120aagaagctga ggaagttctg agtgaaatct cggatattct gaatgatacc
aaccctgcac 3180ctgtgtcatc aagcagctcc ctgtcaagtg ttaggatcac
acgcccaaaa tactcagctc 3240aagccattat cgacttgggc gggccctgca
gtgggcacct ccaaagggaa aaagaagcat 3300gcctccgcat catgcgtgag
gcttgtgatg cggccaagct tagtgaccct gccacgcagg 3360aatggctttc
tcgcatgtgg gatagggtgg acatgctgac ttggcgcaac acgtctgctt
3420accaggcgtt tcgcacctta gatggcaggt ttgggtttct cccaaagatg
atactcgaga 3480cgccgccgcc ctacccgtgt gggtttgtga tgttgcctca
cacccctgca ccttccgtga 3540gtgcagagag cgaccttacc atcggttcag
tcgccactga agatattcca cgcatcctcg 3600ggaaaataga aaataccggt
gagatgatca accagggacc cttggcatcc tctgaggaag 3660aaccggtata
caaccaacct gccaaagact cccggatatc gtcgcggggg tctgacgaga
3720gcacagcagc tccgtccgca ggtacaggtg gcgccggctt atttactgat
ttgccacctt 3780cagacggcgt agatgcggac ggtggggggc cgttgcagac
ggtaagaaag aaagctgaaa 3840ggctcttcga ccaattgagc cgtcaggttt
ttaacctcgt ctcccatctc cctgttttct 3900tctcacacct cttcaaatct
gacagtggtt attctccggg tgattggggt tttgcagctt 3960ttactctatt
ttgcctcttt ttgtgttaca gctacccatt cttcggtttc gttcccctct
4020tgggtgtatt ttctgggtct tctcggcgtg tgcgcatggg ggtttttggc
tgctggctgg 4080cttttgctgt tggcctgttc aagcctgtgt ccgacccagt
cggcactgct tgtgagtttg 4140actcgccaga gtgtaggaac gtccttcatt
cttttgagct tctcaaacct tgggaccctg 4200ttcgcagcct tgttgtgggc
cccgtcggtc tcggtcttgc cattcttggc aggttactgg 4260gcggggcacg
ctacatctgg cattttttgc ttaggcttgg cattgttgca gattgtatct
4320tggctggagc ttatgtgctt tctcaaggta ggtgtaaaaa gtgctgggga
tcttgtataa 4380gaactgctcc taatgaaatc gccttcaacg tgttcccttt
tacacgtgcg accaggtcgt 4440cactcatcga cctgtgcgat cggttttgtg
cgccaaaagg catggacccc attttcctcg 4500ccactgggtg gcgtgggtgc
tggaccggcc gaagtcccat tgagcaaccc tctgaaaaac 4560ccatcgcgtt
cgcccagttg gatgaaaaga ggattacggc tagaactgtg gtcgctcagc
4620cttatgatcc taatcaagcc gtaaagtgct tgcgggtgtt acaggcgggt
ggggcgatgg 4680tggccgaggc agtcccaaaa gtggtcaaag tttctgctat
tccattccga gccccctttt 4740ttcccaccgg agtgaaagtt gatcccgagt
gcaggatcgt ggtcgacccc gatactttta 4800ctacagccct ccggtctggt
tactctacca caaacctcgt ccttggtgtg ggggactttg 4860cccagctgaa
tggactaaag atcaggcaaa tttccaagcc ttcgggagga ggcccacacc
4920tcattgctgc cctgcatgtt gcctgctcga tggcgttgca catgcttgct
ggggtttatg 4980taacttcagt ggggtcttgc ggtgccggca ccaacgatcc
atggtgcact aatccgtttg 5040ccgttcctgg ctacggacca ggctctctct
gcacgtccag attgtgcatc tcccaacatg 5100gccttaccct gcccttgaca
gcacttgtgg cgggattcgg tcttcaggaa atcgccttgg 5160tcgttttgat
tttcgtttcc atcggaggca tggctcatag gttgagttgt aaggctgata
5220tgctgtgcat cttacttgca atcgccagct atgtttgggt accccttacc
tggttgcttt 5280gtgtgtttcc ttgttggttg cgctggttct ctttgcaccc
cctcaccatc ctatggttgg 5340tgtttttctt gatttctgta aatatgcctt
cgggaatctt ggccgtggtg ttattggttt 5400ctctttggct tttgggacgt
tatactaaca ttgctggtct tgtcaccccc tatgatattc 5460atcattacac
cagtggcccc cgcggtgttg ccgccttagc taccgcacca gatggaacct
5520acttggctgc cgtccgccgc gctgcgttga ctggtcgcac catgctgttc
accccgtctc 5580agcttgggtc ccttcttgag ggcgctttca gaactcgaaa
gccctcactg aacaccgtca 5640atgtggttgg gtcctccatg ggctctggtg
gagtgttcac catcgacggg aaaattaggt 5700gcgtgactgc cgcacatgtc
cttacgggta attcggctag ggtttccgga gtcggcttca 5760atcaaatgct
tgactttgat gtgaaagggg acttcgccat agctgattgc ccgaattggc
5820aaggagctgc tcccaagacc caattctgcg aggatggatg ggctggccgt
gcctattggc 5880tgacatcctc tggcgtcgaa cccggtgtta ttgggaatgg
attcgccttc tgcttcaccg 5940cgtgcggcga ttccgggtcc ccagtgatca
ccgaagctgg tgagcttgtc ggcgttcaca 6000caggatcaaa taaacaagga
ggtggcatcg tcacgcgccc ttcaggccag ttttgtaacg 6060tggcacccat
caagctgagc gaattaagtg aattctttgc tggacccaag gtcccgctcg
6120gtgatgtgaa ggttggcagc cacataatta aagatacgtg cgaagtacct
tcagatcttt 6180gcgccttgct tgctgccaaa cctgaactgg agggaggcct
ctccaccgtc caacttctgt 6240gtgtgttttt cctactgtgg agaatgatgg
gacatgcctg gacgcccttg gttgctgtgg 6300ggtttttcat tctgaatgag
gttctcccag ctgtcctggt tcggagtgtt ttctcctttg 6360ggatgtttgt
gctatcttgg ctcacaccat ggtctgcgca agttctgatg atcaggcttc
6420taacagcagc tcttaacagg aacagatggt cacttgcctt ttacagcctt
ggtgcggtga 6480ccggttttgt cgcagatctt gcggcaactc aagggcaccc
gttgcaggca gtaatgaatt 6540tgagcaccta tgccttcctg cctcggatga
tggttgtgac ctcaccagtc ccagtgattg 6600cgtgtggtgt tgtgcaccta
cttgccatca ttttgtactt gttcaagtac cgcggcctgc 6660acaatgttct
tgttggtgat ggagcgtttt ctgcagcttt cttcttgcga tactttgccg
6720agggaaagtt gagggaaggg gtgtcgcaat cctgcggaat gaatcatgag
tcattaactg 6780gtgccctcgc tatgagactc aatgacgagg acttggactt
ccttacgaaa tggactgatt 6840ttaagtgctt tgtttctgcg tccaacatga
ggaatgcagc aggccaattc atcgaggctg 6900cctatgcaaa agcacttaga
attgaacttg cccagttggt gcaggttgat aaggttcgag 6960gtactttggc
caagcttgag gcttttgctg ataccgtggc accccaactc tcgcccggtg
7020acattgttgt tgctcttggc catacgcctg ttggcagcat cttcgaccta
aaggttggtg 7080gtaccaagca tactctccaa gtcattgaga ccagagtcct
tgccgggtcc aaaatgaccg 7140tggcgcgcgt cgttgaccca acccccacgc
ccccacccgc acccgtgccc atccccctcc 7200caccgaaagt tctagagaat
ggtcccaacg cctgggggga tggggaccgt ttgaataaga 7260agaagaggcg
taggatggaa accgtcggca tctttgtcat gggtgggaag aagtaccaga
7320aattttggga caagaattcc ggtgatgtgt tttacgagga ggtccatgac
aacacagatg 7380cgtgggagtg cctcagagtt ggtgaccctg ccgactttga
ccctgagaag ggaactctgt 7440gtgggcatac tactattgaa gataaggatt
acaaagtcta cgcctcccca tctggcaaga 7500agttcctggt ccccgtcaac
tcagagagcg gaagagccca atgggaagct gcaaagcttt 7560ccgtggagca
ggcccttggc atgatgaatg tcgacggtga actgacggcc aaagaagtgg
7620agaaactgaa aagaataatt gacaaacttc agggcctgac taaggagcag
tgtttaaact 7680gctagccgcc agcggcttga cccgctgtgg tcgcggcggc
ttggttgtta ctgagacagc 7740ggtaaaaata gtcaaatttc acaaccggac
tttcacccta gggcctgtga atttaaaagt 7800ggccagtgag gttgagctga
aagacgcggt cgagcacaac caacacccgg ttgcaagacc 7860ggttgacggt
ggtgttgtgc tcctgcgttc cgcagttcct tcgcttatag atgtcctgat
7920ctccggtgct gacgcatctc ctaagttact cgctcgtcac gggccgggga
acactgggat 7980cgatggcacg ctttgggact ttgaggccga ggccaccaaa
gaggaaattg cactcagtgc 8040gcaaataata caggcttgtg acattaggcg
cggcgacgca cctgaaattg gtctccctta 8100caagctgtac cctgttaggg
gcaaccctga gcgggtaaaa ggagttttac agaatacaag 8160gtttggagac
ataccttaca aaacccccag tgacactgga agcccagtgc acgcggctgc
8220ctgcctcacg cccaatgcca ctccggtgac tgatgggcgc tctgtcttgg
ctactaccat 8280gccctccggt tttgaattgt atgtaccgac cattccagcg
tctgtccttg attatcttga 8340ctctaggcct gactgcccca aacagttgac
agagcacggc tgtgaggatg ccgcattgag 8400agacctctcc aagtatgact
tgtccaccca aggctttgtt ttacctgggg ttcttcgcct 8460tgtgcgtaag
tacctgtttg cccatgtggg taagtgcccg cccgttcatc ggccttccac
8520ttaccctgcc aagaattcta tggctggaat aaatgggaac aggtttccaa
ccaaggacat 8580tcagagcgtc cctgaaatcg acgttctgtg cgcacaggcc
gtgcgagaaa actggcaaac 8640tgttacccct tgtaccctca agaaacagta
ttgtgggaag aagaagacta ggacaatact 8700cggcaccaat aatttcattg
cgttggccca ccgggcagcg ttgagtggtg tcacccaggg 8760cttcatgaaa
aaggcgttta actcgcccat cgccctcggg aaaaacaaat ttaaggagct
8820acagactccg gtcttaggca ggtgccttga agctgatctt gcatcctgtg
atcgatccac 8880acctgcaatt gtccgctggt ttgccgccaa tcttctttat
gaacttgcct gtgctgaaga 8940gcacctaccg tcgtacgtgc tgaactgctg
ccatgaccta ttggtcacgc agtccggcgc 9000agtgactaag aggggtggcc
tatcgtctgg cgacccgatc acttctgtgt ctaacaccat 9060ttacagcttg
gtgatatatg cacagcacat ggtgcttagt tactttaaaa gtggtcaccc
9120tcatggcctt ctgttcctac aagaccagct gaagttcgag gacatgctca
aagtccaacc 9180cctgatcgtc tattcggacg acctcgtgct gtatgccgaa
tctcccacca tgccgaacta 9240ccactggtgg gtcgaacatc tgaatttgat
gctgggtttt cagacggacc caaagaagac 9300agccataacg gactcgccat
catttctagg ctgtaggata ataaatggac gccagctagt 9360ccccaaccgt
gacaggatcc tcgcggccct cgcttaccat atgaaggcaa gcaatgtttc
9420tgaatactac gccgcggcgg ctgcaatact catggacagc tgtgcttgtt
tagagtatga 9480tcctgaatgg tttgaagagc ttgtggttgg gatagcgcag
tgcgcccgca aggacggcta 9540cagctttccc ggcccgccgt tcttcttgtc
catgtgggaa aaactcagat ccaatcatga 9600ggggaagaag tccagaatgt
gcgggtattg cggggccccg gctccgtacg ccactgcctg 9660tggcctcgac
gtctgtattt accacaccca cttccaccag cattgtccag tcataatctg
9720gtgtggccac ccggctggtt ctggttcttg tagtgagtgc aaaccccccc
tagggaaagg 9780cacaagccct ctagatgagg tgttagaaca agtcccgtat
aagcctccac ggactgtaat 9840catgcatgtg gagcagggtc tcacccctct
tgacccaggc agataccaga ctcgccgcgg 9900attagtctcc gttaggcgtg
gcatcagagg aaacgaagtt gacctaccag acggtgatta 9960tgctagcacc
gccctactcc ccacttgtaa agagatcaac atggtcgctg tcgcctctaa
10020tgtgttgcgc agcaggttca tcatcggtcc gcccggtgct gggaaaacat
actggctcct 10080tcagcaggtc caggatggtg atgtcattta cacaccgact
caccagacca tgctcgacat 10140gattagggct ttggggacgt gccggttcaa
cgtcccagca ggtacaacgc tgcaattccc 10200tgccccctcc cgtaccggcc
cgtgggttcg catcctggcc ggcggttggt gtcctggtaa 10260gaattccttc
ctggatgaag cagcgtattg taatcacctt gatgtcttga ggctccttag
10320caaaaccacc cttacctgtc tgggagactt caaacaactc cacccagtgg
gttttgattc 10380tcattgctat gtttttgaca tcatgcctca gacccagttg
aagaccatct ggagattcgg 10440acagaacatc tgtgatgcca tccaaccaga
ttacagggac aaacttgtgt ccatggtcaa 10500cacaacccgt gtaacctaca
tggaaaaacc tgtcaagtat gggcaagtcc tcacccctta 10560ccacagggac
cgagaggacg gcgccatcac aattgactcc agtcaaggcg ccacatttga
10620tgtggttaca ctgcatttgc ccactaaaga ttcactcaac aggcaaagag
cccttgttgc 10680tatcaccagg gcaagacatg ctatctttgt gtatgaccca
cacaggcaat tgcagagcat 10740gtttgatctt cctgcgaagg gcacacccgt
caacctcgca gtgcaccgtg atgagcagct 10800gatcgtactg gatagaaata
ataaagaatg cacagttgct caggctatag gcaacggaga 10860taaattcagg
gccaccgaca agcgcgttgt agattctctc cgcgccattt gtgctgatct
10920ggaagggtcg agctccccgc tccccaaggt cgcacacaac ttgggatttt
atttctcacc 10980tgatttgaca cagtttgcta aactcccggt agaccttgca
ccccactggc ccgtggtgac 11040aacccagaac aatgaaaagt ggccggatcg
gctggttgcc agccttcgcc ctgtccataa 11100gtatagccgt gcgtgcattg
gtgccggcta tatggtgggc ccctcggtgt ttctaggcac 11160ccctggggtc
gtgtcatact acctcacaaa atttgtcaag ggcgaggctc aagtgcttcc
11220ggagacagtc ttcagcaccg gccgaattga ggtggattgc cgggagtatc
ttgatgacag 11280ggagcgagaa gttgctgagt ccctcccaca tgccttcatt
ggcgacgtca aaggcaccac 11340cgttggggga tgtcatcatg tcacctccaa
ataccttccg cgcttccttc ccaaggaatc 11400agtcgcggta gtcggggttt
cgagccccgg gaaagccgca aaagcagtgt gcacattgac 11460ggatgtgtac
ctcccagacc ttgaggccta cctccaccca gagactcagt ctaagtgctg
11520gaaagttatg ttggacttca aggaagttcg actgatggtc tggaaagaca
agacggccta 11580tttccaactt gaaggccgct atttcacctg gtatcagctt
gcaagctacg cctcgtacat 11640ccgtgttcct gtcaactcca cggtgtatct
ggacccctgc atgggccctg ccctttgcaa 11700cagaagagtt gtcgggtcca
cccattgggg agctgacctc gcagtcaccc cttatgatta 11760cggtgctaaa
atcatcttgt ctagcgctta ccatggtgaa atgcctcctg gatacaagat
11820tctggcgtgc gcggagttct cgctcgacga cccagtcaag tacaaacaca
cctggggttt 11880tgaatcggat acagcgtatc tgtatgagtt caccggaaac
ggtgaggact gggaggatta 11940caatgatgcg tttcgtgcgc gccagaaagg
gaaaatttat aaggccactg ctaccagcat 12000gaagttttat tttcccccgg
gccccgtcat tgaaccaact ttaggcctga attgaaatga 12060aatggggtct
atacaaagcc tcttcgacaa aattggccag ctttttgtgg atgctttcac
12120ggaatttttg gtgtccattg ttgatatcat catatttttg gccattttgt
ttggcttcac 12180catcgccggt tggctggtgg tcttttgcat cagattggtt
tgctccgcgg tattccgtgc 12240gcgccctgcc attcaccctg agcaattaca
gaagatccta tgaggccttt ctttctcagt 12300gccgggtgga cattcccacc
tggggggtaa aacacccttt ggggatgttt tggcaccata 12360aggtgtcaac
cctgattgat gaaatggtgt cgcgtcgaat gtaccgcatc atggaaaaag
12420cagggcaagc tgcctggaaa caggtggtga gcgaggctac gctgtctcgc
attagtagtt 12480tggatgtggt ggctcatttt caacatcttg ccgccattga
agccgagacc tgtaaatatt 12540tggcttctcg actgcccatg ctacacaacc
tgcgcatgac agggtcaaat gtaaccatag 12600tgtataatag cactttaaat
caggtgtttg ctatttttcc aacccctggt tcccggccaa 12660agcttcatga
ttttcagcaa tggctaatag ctgtacattc ctccatattt tcctctgttg
12720cagcttcttg tactcttttt gttgtgctgt ggttgcgggt tccaatgcta
cgtactgttt 12780ttggtttccg ctggttaggg gcaatttttc tttcgaactc
atggtgaatt acacggtgtg 12840tccaccttgc ctcacccgac aagcagccgc
tgaggtcctt gaacccggta ggtctctttg 12900gtgcaggata gggcatgacc
gatgtgggga ggacgatcac gacgaactag ggttcatggt 12960tccgcctggc
ctctccagcg aaagccactt gaccagtgtt tacgcctggt tggcgttcct
13020gtccttcagc tacacggccc agttccatcc cgagatattt gggataggga
acgtgagtga 13080agtttatgtt gacatcaagc accaattcat ctgcgccgtt
catgacgggc agaacaccac 13140cttgcctcgc catgacaata tttcagccgt
atttcagacc tactatcaac atcaggtcga 13200cggcggcaat tggtttcacc
tagaatggct gcgtcccttc ttttcctctt ggttggtttt 13260aaatgtttcg
tggtttctca ggcgttcgcc tgcaagccat gtttcagttc gagtctttca
13320gacatcaaaa ccaacactac cgcagcatca ggctttgttg tcctccagga
catcagctgc 13380cttaggcatg gcgactcgtc ctttccgacg attcgcaaaa
gctctcaatg ccgcacggcg 13440atagggacac ccgtgtatat caccatcaca
gccaatgtga cagatgagaa ttacttacat 13500tcttctgatc tcctcatgct
ttcttcttgc cttttctatg cttctgagat gagtgaaaag 13560ggattcaagg
tggtgtttgg caatgtgtca ggcatcgtgg ctgtgtgtgt caactttacc
13620agctacgtcc aacatgtcaa agagtttacc caacgctcct tggtggtcga
tcatgtgcgg 13680ctgcttcatt tcatgacacc tgagaccatg aggtgggcaa
ccgttttagc ctgtcttttt 13740gccatcctac tggcaatttg aatgttcaag
tatgttgggg aaatgcttga ccgcgggctg 13800ttgctcgcga ttgctttctt
tgtggtgtat cgtgccgttc tgttttgctg tgctcggcag 13860cgccaacagc
agcagcagct ctcattttca gttgatttat aacttgacgc tatgtgagct
13920gaatggcaca gattggctgg cagaaaaatt tgattgggca gtggagactt
ttgtcatctt 13980tcccgtgttg actcacattg tttcctatgg tgcactcacc
accagccatt tccttgacac 14040agttggtctg gttactgtgt ccaccgccgg
gttttatcac gggcggtatg tcttgagtag 14100catctacgcg gtctgtgctc
tggctgcgtt gatttgcttc gttattaggc ttgcgaagaa 14160ctgcatgtcc
tggcgctact cttgtaccag atataccaac ttccttctgg acactaaggg
14220cagactctat cgttggcggt cgcccgttat catagaaaaa gggggtaagg
ttgaggtcga 14280aggtcacctg atcgacctca aaagagttgt gcttgatggt
tccgtggcaa cccctttaac 14340cagagtttca gcggaacaat ggggtcgtct
ctagacgact tttgccatga tagcacggct 14400ccacaaaagg tgcttttggc
gttttccatt acctacacgc cagtaatgat atatgctcta 14460aaggtaagtc
gcggccgact actagggctt ctgcaccttt tgatctttct gaattgtgct
14520tttaccttcg ggtacatgac attcgagcac tttcagagca caaatagggt
cgcgctcact 14580atgggagcag tagttgcact tctttggggg gtgtactcag
ccatagaaac ctggaaattc 14640atcacctcca gatgccgttt gtgcttgcta
ggccgcaagt acattctggc ccctgcccac 14700cacgtcgaaa gtgccgcggg
ctttcatccg attgcggcaa atgataacca cgcatttgtc 14760gtccggcgtc
ccggctccac tacggttaac ggcacattgg tgcccgggtt gaaaagcctc
14820gtgttgggtg gcagaaaagc tgttaaacag ggagtggtaa accttgtcaa
atatgccaaa 14880taacaacggc aagcagcaaa agaaaaagaa ggggaatggc
cagccagtca atcagctgtg 14940ccagatgctg ggtaaaatca tcgcccagca
aaaccagtcc agaggcaagg gaccgggcaa
15000gaaaagtaag aagaaaaacc cggagaagcc ccattttcct ctagcgaccg
aagatgacgt 15060caggcatcac ttcacccctg gtgagcggca attgtgtctg
tcgtcgatcc agactgcctt 15120taaccagggc gctggaactt gtaccctgtc
agattcaggg aggataagtt acactgtgga 15180gtttagtttg ccgacgcatc
atactgtgcg cctgatccgc gtcacagcat caccctcagc 15240atgatgggct
ggcattcttt aggcacctca gtgtcagaat tggaagaatg tgtggtggat
15300ggcactgatt gacattgtgc ctctaagtca cctattcaat tagggcgacc
gtgtgggggt 15360aaaatttaat tggcgagaac catgcggccg caattaaaaa
aaaaaaaaaa aaaaaaaaaa 15420aaaaaaaaaa aaaaaaaaaa aaaaaaaaaa
1545027494DNAPorcine reproductive and respiratory syndrome virus
2atgtctggga tacttgatcg gtgcacgtgc acccccaatg ccagggtgtt tatggcggag
60ggccaagtct actgcacacg atgtctcagt gcacggtctc tccttcctct gaatctccaa
120gttcctgagc ttggggtgct gggcctattt tataggcccg aagagccact
ccggtggacg 180ttgccacgtg cattccccac tgtcgagtgc tcccccgccg
gggcctgctg gctttctgcg 240atctttccaa ttgcacgaat gaccagtgga
aacctgaact ttcaacaaag aatggtgcgg 300gttgcagctg agatttacag
agccggccaa ctcacccctg cagttttgaa ggctctacaa 360gtttatgaac
ggggttgtcg ctggtacccc attgtcggac ctgtccctgg agtggccgtt
420cacgccaact ccctacatgt gagtgacaaa cctttcccgg gagcaactca
tgtgttaacc 480aacctaccgc tcccgcagag gcccaagcct gaagactttt
gcccttttga gtgtgctatg 540gctgacgtct atgacattag ccatgacgcc
gtcatgtatg tggccagagg gaaagtctcc 600tgggcccctc gtggcgggga
tgaagtgaaa tttgaaaccg tccccgaaga gttgaagttg 660attgcgaacc
gactccacat ctccttcccg ccccaccacg cagtggacat gtctgagttt
720gccttcatag cccctgggag tggtgtctcc ttgcgggtcg agcaccaaca
cggttgcctt 780cccgctgata ctgtccctga agggaactgc tggtggtgct
tgtttgactt gctcccaccg 840gaagttcaga ataaagaaat tcgccgtgct
aaccaatttg gctatcaaac caagcatggt 900gtccctggca agtacctaca
gcggaggctg caagttaatg gtctccgagc agtgactgat 960acagatggac
ctattgtcgt acagtacttc tctgttaggg agagttggat ccgccacttc
1020agactggcgg aagaacctag cctccctggg tttgaagacc tcctcagaat
aagggtagag 1080cctaatacgt cgccattggg tggcaagggt gaaaaaatct
tccggtttgg cagtcacaag 1140tggtacggtg ctggaaagag agcaaggaga
gcacgctctg gtgcaactgc cacggtcgct 1200cactgcgctt tgcccgctcg
cgaagcccag caggccaaga agctcgaggt tgccagcgcc 1260aacagggctg
agcatctcaa gtactattcc ccgcctgccg acgggaactg tggttggcac
1320tgcatttccg ccattaccaa ccggatggtg aattccaaat ttgaaaccac
tcttcccgag 1380agagtgagac cttcagatga ctgggctact gacgaggatc
ttgtgaatac catccaaatc 1440ctcaggctcc ccgcggcctt ggacaggaac
ggtgcttgtg ctggcgccaa gtacgtgctc 1500aagctggaag gtgagcactg
gaccgtctct gtgacccctg ggatgacccc ttctttgctc 1560ccccttgaat
gtgttcaggg ttgttgtgag cataagagcg gtcttggttt cccagacgtg
1620gtcgaagttt ccggatttga ccctgcctgt cttgaccgac ttgctgagat
aatgcactta 1680cctagcagtg tcatcccagc tgctctggcc gagatgtccg
acgacttcaa tcgtctggct 1740tccccggccg ccactgtgtg gactgtttcg
caattctttg cccgccacag aggaggagag 1800catcctgacc aggtgtgctt
agggaaaatt atcaaccttt gtcaggtgat tgaggaatgc 1860tgctgttccc
ggaacaaagc caaccgggct accccggaag aggttgcggc aaaagttgac
1920cagtacctcc gtggtgcagc aagccttgga gaatgcttgg ccaagcttga
gagggctcgc 1980ccgccgagcg cgatggacac ctcctttgat tggaatgttg
tgcttcctgg ggttgagacg 2040gcggatcaga caaccaaaca gctccatgtc
aaccagtgcc gcgctctggt tcctgtcgtg 2100actcaagagc ctttggacag
agactcggtc cctctgaccg ccttctcgct gtccaattgc 2160tactaccctg
cacaaggtga cgaggtccgt caccgtgaga ggctaaactc cgtgctctct
2220aagttggagg gggttgttcg tgaggaatat gggctcacgc caactggacc
tggcccgcga 2280cccgcactgc cgaacgggct cgacgagctt aaagaccaga
tggaggagga tctgctgaaa 2340ttagtcaacg cccaggcaac ttcagaaatg
atggcctggg cagccgagca ggttgatcta 2400aaagcttggg tcaaaaatta
cccacggtgg acaccgccac cccctccacc aagagttcag 2460cctcgaaaaa
cgaagtctgt caagagcttg ctagagaaca agcctgtccc tgctccgcgc
2520aggaaggtca gatctgatta tggcagcccg attttgatgg gcgacaatgt
tcctaacggt 2580tgggaagatt cgactgttgg tggtcccctt gacctttcgg
caccatccga gccgatgaca 2640cctctgagtg agcctgtact tatttccagg
ccagtgacat ctttgagtgt gccggcccca 2700gttcctgcac cgcgtagagc
tgtgtctcga ccgatgacgc cctcgagtga gccaattttt 2760gtgtctgcac
tgcgacacaa atttcagcag gtggaaaaag caaatctggc ggcagcagcg
2820ccgatgtacc aggacgaacc cttagatttg tctgcatcct cacagactga
atatggggct 2880tctcccctaa caccaccgca gaacgtgggc attctggagg
taagggggca agaagctgag 2940gaagttctga gtgaaatctc ggatattctg
aatgatacca accctgcacc tgtgtcatca 3000agcagctccc tgtcaagtgt
taggatcaca cgcccaaaat actcagctca agccattatc 3060gacttgggcg
ggccctgcag tgggcacctc caaagggaaa aagaagcatg cctccgcatc
3120atgcgtgagg cttgtgatgc ggccaagctt agtgaccctg ccacgcagga
atggctttct 3180cgcatgtggg atagggtgga catgctgact tggcgcaaca
cgtctgctta ccaggcgttt 3240cgcaccttag atggcaggtt tgggtttctc
ccaaagatga tactcgagac gccgccgccc 3300tacccgtgtg ggtttgtgat
gttgcctcac acccctgcac cttccgtgag tgcagagagc 3360gaccttacca
tcggttcagt cgccactgaa gatattccac gcatcctcgg gaaaatagaa
3420aataccggtg agatgatcaa ccagggaccc ttggcatcct ctgaggaaga
accggtatac 3480aaccaacctg ccaaagactc ccggatatcg tcgcgggggt
ctgacgagag cacagcagct 3540ccgtccgcag gtacaggtgg cgccggctta
tttactgatt tgccaccttc agacggcgta 3600gatgcggacg gtggggggcc
gttgcagacg gtaagaaaga aagctgaaag gctcttcgac 3660caattgagcc
gtcaggtttt taacctcgtc tcccatctcc ctgttttctt ctcacacctc
3720ttcaaatctg acagtggtta ttctccgggt gattggggtt ttgcagcttt
tactctattt 3780tgcctctttt tgtgttacag ctacccattc ttcggtttcg
ttcccctctt gggtgtattt 3840tctgggtctt ctcggcgtgt gcgcatgggg
gtttttggct gctggctggc ttttgctgtt 3900ggcctgttca agcctgtgtc
cgacccagtc ggcactgctt gtgagtttga ctcgccagag 3960tgtaggaacg
tccttcattc ttttgagctt ctcaaacctt gggaccctgt tcgcagcctt
4020gttgtgggcc ccgtcggtct cggtcttgcc attcttggca ggttactggg
cggggcacgc 4080tacatctggc attttttgct taggcttggc attgttgcag
attgtatctt ggctggagct 4140tatgtgcttt ctcaaggtag gtgtaaaaag
tgctggggat cttgtataag aactgctcct 4200aatgaaatcg ccttcaacgt
gttccctttt acacgtgcga ccaggtcgtc actcatcgac 4260ctgtgcgatc
ggttttgtgc gccaaaaggc atggacccca ttttcctcgc cactgggtgg
4320cgtgggtgct ggaccggccg aagtcccatt gagcaaccct ctgaaaaacc
catcgcgttc 4380gcccagttgg atgaaaagag gattacggct agaactgtgg
tcgctcagcc ttatgatcct 4440aatcaagccg taaagtgctt gcgggtgtta
caggcgggtg gggcgatggt ggccgaggca 4500gtcccaaaag tggtcaaagt
ttctgctatt ccattccgag cccccttttt tcccaccgga 4560gtgaaagttg
atcccgagtg caggatcgtg gtcgaccccg atacttttac tacagccctc
4620cggtctggtt actctaccac aaacctcgtc cttggtgtgg gggactttgc
ccagctgaat 4680ggactaaaga tcaggcaaat ttccaagcct tcgggaggag
gcccacacct cattgctgcc 4740ctgcatgttg cctgctcgat ggcgttgcac
atgcttgctg gggtttatgt aacttcagtg 4800gggtcttgcg gtgccggcac
caacgatcca tggtgcacta atccgtttgc cgttcctggc 4860tacggaccag
gctctctctg cacgtccaga ttgtgcatct cccaacatgg ccttaccctg
4920cccttgacag cacttgtggc gggattcggt cttcaggaaa tcgccttggt
cgttttgatt 4980ttcgtttcca tcggaggcat ggctcatagg ttgagttgta
aggctgatat gctgtgcatc 5040ttacttgcaa tcgccagcta tgtttgggta
ccccttacct ggttgctttg tgtgtttcct 5100tgttggttgc gctggttctc
tttgcacccc ctcaccatcc tatggttggt gtttttcttg 5160atttctgtaa
atatgccttc gggaatcttg gccgtggtgt tattggtttc tctttggctt
5220ttgggacgtt atactaacat tgctggtctt gtcaccccct atgatattca
tcattacacc 5280agtggccccc gcggtgttgc cgccttagct accgcaccag
atggaaccta cttggctgcc 5340gtccgccgcg ctgcgttgac tggtcgcacc
atgctgttca ccccgtctca gcttgggtcc 5400cttcttgagg gcgctttcag
aactcgaaag ccctcactga acaccgtcaa tgtggttggg 5460tcctccatgg
gctctggtgg agtgttcacc atcgacggga aaattaggtg cgtgactgcc
5520gcacatgtcc ttacgggtaa ttcggctagg gtttccggag tcggcttcaa
tcaaatgctt 5580gactttgatg tgaaagggga cttcgccata gctgattgcc
cgaattggca aggagctgct 5640cccaagaccc aattctgcga ggatggatgg
gctggccgtg cctattggct gacatcctct 5700ggcgtcgaac ccggtgttat
tgggaatgga ttcgccttct gcttcaccgc gtgcggcgat 5760tccgggtccc
cagtgatcac cgaagctggt gagcttgtcg gcgttcacac aggatcaaat
5820aaacaaggag gtggcatcgt cacgcgccct tcaggccagt tttgtaacgt
ggcacccatc 5880aagctgagcg aattaagtga attctttgct ggacccaagg
tcccgctcgg tgatgtgaag 5940gttggcagcc acataattaa agatacgtgc
gaagtacctt cagatctttg cgccttgctt 6000gctgccaaac ctgaactgga
gggaggcctc tccaccgtcc aacttctgtg tgtgtttttc 6060ctactgtgga
gaatgatggg acatgcctgg acgcccttgg ttgctgtggg gtttttcatt
6120ctgaatgagg ttctcccagc tgtcctggtt cggagtgttt tctcctttgg
gatgtttgtg 6180ctatcttggc tcacaccatg gtctgcgcaa gttctgatga
tcaggcttct aacagcagct 6240cttaacagga acagatggtc acttgccttt
tacagccttg gtgcggtgac cggttttgtc 6300gcagatcttg cggcaactca
agggcacccg ttgcaggcag taatgaattt gagcacctat 6360gccttcctgc
ctcggatgat ggttgtgacc tcaccagtcc cagtgattgc gtgtggtgtt
6420gtgcacctac ttgccatcat tttgtacttg ttcaagtacc gcggcctgca
caatgttctt 6480gttggtgatg gagcgttttc tgcagctttc ttcttgcgat
actttgccga gggaaagttg 6540agggaagggg tgtcgcaatc ctgcggaatg
aatcatgagt cattaactgg tgccctcgct 6600atgagactca atgacgagga
cttggacttc cttacgaaat ggactgattt taagtgcttt 6660gtttctgcgt
ccaacatgag gaatgcagca ggccaattca tcgaggctgc ctatgcaaaa
6720gcacttagaa ttgaacttgc ccagttggtg caggttgata aggttcgagg
tactttggcc 6780aagcttgagg cttttgctga taccgtggca ccccaactct
cgcccggtga cattgttgtt 6840gctcttggcc atacgcctgt tggcagcatc
ttcgacctaa aggttggtgg taccaagcat 6900actctccaag tcattgagac
cagagtcctt gccgggtcca aaatgaccgt ggcgcgcgtc 6960gttgacccaa
cccccacgcc cccacccgca cccgtgccca tccccctccc accgaaagtt
7020ctagagaatg gtcccaacgc ctggggggat ggggaccgtt tgaataagaa
gaagaggcgt 7080aggatggaaa ccgtcggcat ctttgtcatg ggtgggaaga
agtaccagaa attttgggac 7140aagaattccg gtgatgtgtt ttacgaggag
gtccatgaca acacagatgc gtgggagtgc 7200ctcagagttg gtgaccctgc
cgactttgac cctgagaagg gaactctgtg tgggcatact 7260actattgaag
ataaggatta caaagtctac gcctccccat ctggcaagaa gttcctggtc
7320cccgtcaact cagagagcgg aagagcccaa tgggaagctg caaagctttc
cgtggagcag 7380gcccttggca tgatgaatgt cgacggtgaa ctgacggcca
aagaagtgga gaaactgaaa 7440agaataattg acaaacttca gggcctgact
aaggagcagt gtttaaactg ctag 749434392DNAPorcine reproductive and
respiratory syndrome virus 3ggagcagtgt ttaaactgct agccgccagc
ggcttgaccc gctgtggtcg cggcggcttg 60gttgttactg agacagcggt aaaaatagtc
aaatttcaca accggacttt caccctaggg 120cctgtgaatt taaaagtggc
cagtgaggtt gagctgaaag acgcggtcga gcacaaccaa 180cacccggttg
caagaccggt tgacggtggt gttgtgctcc tgcgttccgc agttccttcg
240cttatagatg tcctgatctc cggtgctgac gcatctccta agttactcgc
tcgtcacggg 300ccggggaaca ctgggatcga tggcacgctt tgggactttg
aggccgaggc caccaaagag 360gaaattgcac tcagtgcgca aataatacag
gcttgtgaca ttaggcgcgg cgacgcacct 420gaaattggtc tcccttacaa
gctgtaccct gttaggggca accctgagcg ggtaaaagga 480gttttacaga
atacaaggtt tggagacata ccttacaaaa cccccagtga cactggaagc
540ccagtgcacg cggctgcctg cctcacgccc aatgccactc cggtgactga
tgggcgctct 600gtcttggcta ctaccatgcc ctccggtttt gaattgtatg
taccgaccat tccagcgtct 660gtccttgatt atcttgactc taggcctgac
tgccccaaac agttgacaga gcacggctgt 720gaggatgccg cattgagaga
cctctccaag tatgacttgt ccacccaagg ctttgtttta 780cctggggttc
ttcgccttgt gcgtaagtac ctgtttgccc atgtgggtaa gtgcccgccc
840gttcatcggc cttccactta ccctgccaag aattctatgg ctggaataaa
tgggaacagg 900tttccaacca aggacattca gagcgtccct gaaatcgacg
ttctgtgcgc acaggccgtg 960cgagaaaact ggcaaactgt taccccttgt
accctcaaga aacagtattg tgggaagaag 1020aagactagga caatactcgg
caccaataat ttcattgcgt tggcccaccg ggcagcgttg 1080agtggtgtca
cccagggctt catgaaaaag gcgtttaact cgcccatcgc cctcgggaaa
1140aacaaattta aggagctaca gactccggtc ttaggcaggt gccttgaagc
tgatcttgca 1200tcctgtgatc gatccacacc tgcaattgtc cgctggtttg
ccgccaatct tctttatgaa 1260cttgcctgtg ctgaagagca cctaccgtcg
tacgtgctga actgctgcca tgacctattg 1320gtcacgcagt ccggcgcagt
gactaagagg ggtggcctat cgtctggcga cccgatcact 1380tctgtgtcta
acaccattta cagcttggtg atatatgcac agcacatggt gcttagttac
1440tttaaaagtg gtcaccctca tggccttctg ttcctacaag accagctgaa
gttcgaggac 1500atgctcaaag tccaacccct gatcgtctat tcggacgacc
tcgtgctgta tgccgaatct 1560cccaccatgc cgaactacca ctggtgggtc
gaacatctga atttgatgct gggttttcag 1620acggacccaa agaagacagc
cataacggac tcgccatcat ttctaggctg taggataata 1680aatggacgcc
agctagtccc caaccgtgac aggatcctcg cggccctcgc ttaccatatg
1740aaggcaagca atgtttctga atactacgcc gcggcggctg caatactcat
ggacagctgt 1800gcttgtttag agtatgatcc tgaatggttt gaagagcttg
tggttgggat agcgcagtgc 1860gcccgcaagg acggctacag ctttcccggc
ccgccgttct tcttgtccat gtgggaaaaa 1920ctcagatcca atcatgaggg
gaagaagtcc agaatgtgcg ggtattgcgg ggccccggct 1980ccgtacgcca
ctgcctgtgg cctcgacgtc tgtatttacc acacccactt ccaccagcat
2040tgtccagtca taatctggtg tggccacccg gctggttctg gttcttgtag
tgagtgcaaa 2100ccccccctag ggaaaggcac aagccctcta gatgaggtgt
tagaacaagt cccgtataag 2160cctccacgga ctgtaatcat gcatgtggag
cagggtctca cccctcttga cccaggcaga 2220taccagactc gccgcggatt
agtctccgtt aggcgtggca tcagaggaaa cgaagttgac 2280ctaccagacg
gtgattatgc tagcaccgcc ctactcccca cttgtaaaga gatcaacatg
2340gtcgctgtcg cctctaatgt gttgcgcagc aggttcatca tcggtccgcc
cggtgctggg 2400aaaacatact ggctccttca gcaggtccag gatggtgatg
tcatttacac accgactcac 2460cagaccatgc tcgacatgat tagggctttg
gggacgtgcc ggttcaacgt cccagcaggt 2520acaacgctgc aattccctgc
cccctcccgt accggcccgt gggttcgcat cctggccggc 2580ggttggtgtc
ctggtaagaa ttccttcctg gatgaagcag cgtattgtaa tcaccttgat
2640gtcttgaggc tccttagcaa aaccaccctt acctgtctgg gagacttcaa
acaactccac 2700ccagtgggtt ttgattctca ttgctatgtt tttgacatca
tgcctcagac ccagttgaag 2760accatctgga gattcggaca gaacatctgt
gatgccatcc aaccagatta cagggacaaa 2820cttgtgtcca tggtcaacac
aacccgtgta acctacatgg aaaaacctgt caagtatggg 2880caagtcctca
ccccttacca cagggaccga gaggacggcg ccatcacaat tgactccagt
2940caaggcgcca catttgatgt ggttacactg catttgccca ctaaagattc
actcaacagg 3000caaagagccc ttgttgctat caccagggca agacatgcta
tctttgtgta tgacccacac 3060aggcaattgc agagcatgtt tgatcttcct
gcgaagggca cacccgtcaa cctcgcagtg 3120caccgtgatg agcagctgat
cgtactggat agaaataata aagaatgcac agttgctcag 3180gctataggca
acggagataa attcagggcc accgacaagc gcgttgtaga ttctctccgc
3240gccatttgtg ctgatctgga agggtcgagc tccccgctcc ccaaggtcgc
acacaacttg 3300ggattttatt tctcacctga tttgacacag tttgctaaac
tcccggtaga ccttgcaccc 3360cactggcccg tggtgacaac ccagaacaat
gaaaagtggc cggatcggct ggttgccagc 3420cttcgccctg tccataagta
tagccgtgcg tgcattggtg ccggctatat ggtgggcccc 3480tcggtgtttc
taggcacccc tggggtcgtg tcatactacc tcacaaaatt tgtcaagggc
3540gaggctcaag tgcttccgga gacagtcttc agcaccggcc gaattgaggt
ggattgccgg 3600gagtatcttg atgacaggga gcgagaagtt gctgagtccc
tcccacatgc cttcattggc 3660gacgtcaaag gcaccaccgt tgggggatgt
catcatgtca cctccaaata ccttccgcgc 3720ttccttccca aggaatcagt
cgcggtagtc ggggtttcga gccccgggaa agccgcaaaa 3780gcagtgtgca
cattgacgga tgtgtacctc ccagaccttg aggcctacct ccacccagag
3840actcagtcta agtgctggaa agttatgttg gacttcaagg aagttcgact
gatggtctgg 3900aaagacaaga cggcctattt ccaacttgaa ggccgctatt
tcacctggta tcagcttgca 3960agctacgcct cgtacatccg tgttcctgtc
aactccacgg tgtatctgga cccctgcatg 4020ggccctgccc tttgcaacag
aagagttgtc gggtccaccc attggggagc tgacctcgca 4080gtcacccctt
atgattacgg tgctaaaatc atcttgtcta gcgcttacca tggtgaaatg
4140cctcctggat acaagattct ggcgtgcgcg gagttctcgc tcgacgaccc
agtcaagtac 4200aaacacacct ggggttttga atcggataca gcgtatctgt
atgagttcac cggaaacggt 4260gaggactggg aggattacaa tgatgcgttt
cgtgcgcgcc agaaagggaa aatttataag 4320gccactgcta ccagcatgaa
gttttatttt cccccgggcc ccgtcattga accaacttta 4380ggcctgaatt ga
43924771DNAPorcine reproductive and respiratory syndrome virus
4atgaaatggg gtctatacaa agcctcttcg acaaaattgg ccagcttttt gtggatgctt
60tcacggaatt tttggtgtcc attgttgata tcatcatatt tttggccatt ttgtttggct
120tcaccatcgc cggttggctg gtggtctttt gcatcagatt ggtttgctcc
gcggtattcc 180gtgcgcgccc tgccattcac cctgagcaat tacagaagat
cctatgaggc ctttctttct 240cagtgccggg tggacattcc cacctggggg
gtaaaacacc ctttggggat gttttggcac 300cataaggtgt caaccctgat
tgatgaaatg gtgtcgcgtc gaatgtaccg catcatggaa 360aaagcagggc
aagctgcctg gaaacaggtg gtgagcgagg ctacgctgtc tcgcattagt
420agtttggatg tggtggctca ttttcaacat cttgccgcca ttgaagccga
gacctgtaaa 480tatttggctt ctcgactgcc catgctacac aacctgcgca
tgacagggtc aaatgtaacc 540atagtgtata atagcacttt aaatcaggtg
tttgctattt ttccaacccc tggttcccgg 600ccaaagcttc atgattttca
gcaatggcta atagctgtac attcctccat attttcctct 660gttgcagctt
cttgtactct ttttgttgtg ctgtggttgc gggttccaat gctacgtact
720gtttttggtt tccgctggtt aggggcaatt tttctttcga actcatggtg a
7715765DNAPorcine reproductive and respiratory syndrome virus
5atggctaata gctgtacatt cctccatatt ttcctctgtt gcagcttctt gtactctttt
60tgttgtgctg tggttgcggg ttccaatgct acgtactgtt tttggtttcc gctggttagg
120ggcaattttt ctttcgaact catggtgaat tacacggtgt gtccaccttg
cctcacccga 180caagcagccg ctgaggtcct tgaacccggt aggtctcttt
ggtgcaggat agggcatgac 240cgatgtgggg aggacgatca cgacgaacta
gggttcatgg ttccgcctgg cctctccagc 300gaaagccact tgaccagtgt
ttacgcctgg ttggcgttcc tgtccttcag ctacacggcc 360cagttccatc
ccgagatatt tgggataggg aacgtgagtg aagtttatgt tgacatcaag
420caccaattca tctgcgccgt tcatgacggg cagaacacca ccttgcctcg
ccatgacaat 480atttcagccg tatttcagac ctactatcaa catcaggtcg
acggcggcaa ttggtttcac 540ctagaatggc tgcgtccctt cttttcctct
tggttggttt taaatgtttc gtggtttctc 600aggcgttcgc ctgcaagcca
tgtttcagtt cgagtctttc agacatcaaa accaacacta 660ccgcagcatc
aggctttgtt gtcctccagg acatcagctg ccttaggcat ggcgactcgt
720cctttccgac gattcgcaaa agctctcaat gccgcacggc gatag
7656537DNAPorcine reproductive and respiratory syndrome virus
6atggctgcgt cccttctttt cctcttggtt ggttttaaat gtttcgtggt ttctcaggcg
60ttcgcctgca agccatgttt cagttcgagt ctttcagaca tcaaaaccaa cactaccgca
120gcatcaggct ttgttgtcct ccaggacatc agctgcctta ggcatggcga
ctcgtccttt 180ccgacgattc gcaaaagctc tcaatgccgc acggcgatag
ggacacccgt gtatatcacc 240atcacagcca atgtgacaga tgagaattac
ttacattctt ctgatctcct catgctttct 300tcttgccttt tctatgcttc
tgagatgagt gaaaagggat tcaaggtggt gtttggcaat 360gtgtcaggca
tcgtggctgt gtgtgtcaac tttaccagct acgtccaaca tgtcaaagag
420tttacccaac gctccttggt ggtcgatcat gtgcggctgc ttcatttcat
gacacctgag 480accatgaggt gggcaaccgt tttagcctgt ctttttgcca
tcctactggc aatttga 5377603DNAPorcine reproductive and respiratory
syndrome virus 7atgttgggga aatgcttgac cgcgggctgt tgctcgcgat
tgctttcttt gtggtgtatc 60gtgccgttct gttttgctgt gctcggcagc gccaacagca
gcagcagctc tcattttcag 120ttgatttata acttgacgct atgtgagctg
aatggcacag attggctggc agaaaaattt 180gattgggcag
tggagacttt tgtcatcttt cccgtgttga ctcacattgt ttcctatggt
240gcactcacca ccagccattt ccttgacaca gttggtctgg ttactgtgtc
caccgccggg 300ttttatcacg ggcggtatgt cttgagtagc atctacgcgg
tctgtgctct ggctgcgttg 360atttgcttcg ttattaggct tgcgaagaac
tgcatgtcct ggcgctactc ttgtaccaga 420tataccaact tccttctgga
cactaagggc agactctatc gttggcggtc gcccgttatc 480atagaaaaag
ggggtaaggt tgaggtcgaa ggtcacctga tcgacctcaa aagagttgtg
540cttgatggtt ccgtggcaac ccctttaacc agagtttcag cggaacaatg
gggtcgtctc 600tag 6038525DNAPorcine reproductive and respiratory
syndrome virus 8atggggtcgt ctctagacga cttttgccat gatagcacgg
ctccacaaaa ggtgcttttg 60gcgttttcca ttacctacac gccagtaatg atatatgctc
taaaggtaag tcgcggccga 120ctactagggc ttctgcacct tttgatcttt
ctgaattgtg cttttacctt cgggtacatg 180acattcgagc actttcagag
cacaaatagg gtcgcgctca ctatgggagc agtagttgca 240cttctttggg
gggtgtactc agccatagaa acctggaaat tcatcacctc cagatgccgt
300ttgtgcttgc taggccgcaa gtacattctg gcccctgccc accacgtcga
aagtgccgcg 360ggctttcatc cgattgcggc aaatgataac cacgcatttg
tcgtccggcg tcccggctcc 420actacggtta acggcacatt ggtgcccggg
ttgaaaagcc tcgtgttggg tggcagaaaa 480gctgttaaac agggagtggt
aaaccttgtc aaatatgcca aataa 5259372DNAPorcine reproductive and
respiratory syndrome virus 9atgccaaata acaacggcaa gcagcaaaag
aaaaagaagg ggaatggcca gccagtcaat 60cagctgtgcc agatgctggg taaaatcatc
gcccagcaaa accagtccag aggcaaggga 120ccgggcaaga aaagtaagaa
gaaaaacccg gagaagcccc attttcctct agcgaccgaa 180gatgacgtca
ggcatcactt cacccctggt gagcggcaat tgtgtctgtc gtcgatccag
240actgccttta accagggcgc tggaacttgt accctgtcag attcagggag
gataagttac 300actgtggagt ttagtttgcc gacgcatcat actgtgcgcc
tgatccgcgt cacagcatca 360ccctcagcat ga 3721018DNAPorcine
reproductive and respiratory syndrome virus 10acagtttggt gatctatg
181117DNAPorcine reproductive and respiratory syndrome virus
11cagattcaga tgttcaa 171224DNAPorcine reproductive and respiratory
syndrome virus 12acctcgtgct gtatgccgaa tctc 241324DNAPorcine
reproductive and respiratory syndrome virus 13tcaggcctaa agttggttca
atga 241424DNAPorcine reproductive and respiratory syndrome virus
14gatgactggg ctactgacga ggat 241521DNAPorcine reproductive and
respiratory syndrome virus 15agagcggctg ggatgacact g
211622DNAPorcine reproductive and respiratory syndrome virus
16ccggggaagc cagacgattg aa 221724DNAPorcine reproductive and
respiratory syndrome virus 17agggggagca aagaaggggt catc
241820DNAPorcine reproductive and respiratory syndrome virus
18agcacgctct ggtgcaactg 201919DNAPorcine reproductive and
respiratory syndrome virus 19gccgcggcgt agtattcag 192022DNAPorcine
reproductive and respiratory syndrome virus 20cgcgtcacag catcaccctc
ag 222125DNAPorcine reproductive and respiratory syndrome virus
21cggtaggttg gttaacacat gagtt 252223DNAPorcine reproductive and
respiratory syndrome virus 22tggctcttcg ggcctataaa ata
232356DNAPorcine reproductive and respiratory syndrome virus
23ctagattaat taatacgact cactataggg atgacgtata ggtgttggct ctatgc
562456DNAPorcine reproductive and respiratory syndrome virus
24taattaatta tgctgagtga tatccctact gcatatccac aaccgagata cggtgc
562527DNAPorcine reproductive and respiratory syndrome virus
25actcagtcta agtgctggaa agttatg 272659DNAPorcine reproductive and
respiratory syndrome virus 26gggatttaaa tatgcatttt tttttttttt
tttttttaat tgcggccgca tggttctcg 592736DNAPorcine reproductive and
respiratory syndrome virus 27attagatctt gccaccatgg tggggaaatg
cttgac 362846DNAPorcine reproductive and respiratory syndrome virus
28ctttacgcgt ttgcttaagt tatttggcgt atttgacaag gtttac
462931DNAPorcine reproductive and respiratory syndrome virus
29caacacgcgt cagcaaaaga aaaagaaggg g 313020DNAPorcine reproductive
and respiratory syndrome virus 30gcgcgttggc cgattcatta
203137DNAPorcine reproductive and respiratory syndrome virus
31ctcgttaatt aaaccgtcat gacgtatagg tgttggc 37323796DNAPorcine
reproductive and respiratory syndrome virus 32gaattcgagc ttgcatgcct
gcaggtcgtt acataactta cggtaaatgg cccgcctggc 60tgaccgccca acgacccccg
cccattgacg tcaataatga cgtatgttcc catagtaacg 120ccaataggga
ctttccattg acgtcaatgg gtggagtatt tacggtaaac tgcccacttg
180gcagtacatc aagtgtatca tatgccaagt acgcccccta ttgacgtcaa
tgacggtaaa 240tggcccgcct ggcattatgc ccagtacatg accttatggg
actttcctac ttggcagtac 300atctacgtat tagtcatcgc tattaccatg
gtgatgcggt tttggcagta catcaatggg 360cgtggatagc ggtttgactc
acggggattt ccaagtctcc accccattga cgtcaatggg 420agtttgtttt
ggcaccaaaa tcaacgggac tttccaaaat gtcgtaacaa ctccgcccca
480ttgacgcaaa tgggcggtag gcgtgtacgg tgggaggtct atataagcag
agctcgttta 540gtgaaccgtc agatcgcctg gagacgccat ccacgctgtt
ttgacctcca tagaagacac 600cgggaccgat ccagcctccg gactctagag
gatccggtac tcgaggaact gaaaaaccag 660aaagttaact ggtaagttta
gtctttttgt cttttatttc aggtcccgga tccggtggtg 720gtgcaaatca
aagaactgct cctcagtgga tgttgccttt acttctaggc ctgtacggaa
780gtgttacttc tgctctaaaa gctgcggaat tgtacccgcg gccgcaagat
atcgccctag 840gaagatctcg atcgattggt accaatccgc gaccccttaa
ttaacagcta gcggatttaa 900atcagggccc gggatactag tgagcggccg
cggggatcca gacatgataa gatacattga 960tgagtttgga caaaccacaa
ctagaatgca gtgaaaaaaa tgctttattt gtgaaatttg 1020tgatgctatt
gctttatttg taaccattat aagctgcaat aaacaagtta acaacaacaa
1080ttgcattcat tttatgtttc aggttcaggg ggaggtgtgg gaggtttttt
cggatcctct 1140agagtcgacc tgcaggcatg caagcttggc gtaatcatgg
tcatagctgt ttcctgtgtg 1200aaattgttat ccgctcacaa ttccacacaa
catacgagcc ggaagcataa agtgtaaagc 1260ctggggtgcc taatgagtga
gctaactcac attaattgcg ttgcgctcac tgcccgcttt 1320ccagtcggga
aacctgtcgt gccagctgca ttaatgaatc ggccaacgcg cggggagagg
1380cggtttgcgt attgggcgct cttccgcttc ctcgctcact gactcgctgc
gctcggtcgt 1440tcggctgcgg cgagcggtat cagctcactc aaaggcggta
atacggttat ccacagaatc 1500aggggataac gcaggaaaga acatgtgagc
aaaaggccag caaaaggcca ggaaccgtaa 1560aaaggccgcg ttgctggcgt
ttttccatag gctccgcccc cctgacgagc atcacaaaaa 1620tcgacgctca
agtcagaggt ggcgaaaccc gacaggacta taaagatacc aggcgtttcc
1680ccctggaagc tccctcgtgc gctctcctgt tccgaccctg ccgcttaccg
gatacctgtc 1740cgcctttctc ccttcgggaa gcgtggcgct ttctcatagc
tcacgctgta ggtatctcag 1800ttcggtgtag gtcgttcgct ccaagctggg
ctgtgtgcac gaaccccccg ttcagcccga 1860ccgctgcgcc ttatccggta
actatcgtct tgagtccaac ccggtaagac acgacttatc 1920gccactggca
gcagccactg gtaacaggat tagcagagcg aggtatgtag gcggtgctac
1980agagttcttg aagtggtggc ctaactacgg ctacactaga aggacagtat
ttggtatctg 2040cgctctgctg aagccagtta ccttcggaaa aagagttggt
agctcttgat ccggcaaaca 2100aaccaccgct ggtagcggtg gtttttttgt
ttgcaagcag cagattacgc gcagaaaaaa 2160aggatctcaa gaagatcctt
tgatcttttc tacggggtct gacgctcagt ggaacgaaaa 2220ctcacgttaa
gggattttgg tcatgagatt atcaaaaagg atcttcacct agatcctttt
2280aaattaaaaa tgaagtttta aatcaatcta aagtatatat gagtaaactt
ggtctgacag 2340ttaccaatgc ttaatcagtg aggcacctat ctcagcgatc
tgtctatttc gttcatccat 2400agttgcctga ctccccgtcg tgtagataac
tacgatacgg gagggcttac catctggccc 2460cagtgctgca atgataccgc
gagacccacg ctcaccggct ccagatttat cagcaataaa 2520ccagccagcc
ggaagggccg agcgcagaag tggtcctgca actttatccg cctccatcca
2580gtctattaat tgttgccggg aagctagagt aagtagttcg ccagttaata
gtttgcgcaa 2640cgttgttgcc attgctacag gcatcgtggt gtcacgctcg
tcgtttggta tggcttcatt 2700cagctccggt tcccaacgat caaggcgagt
tacatgatcc cccatgttgt gcaaaaaagc 2760ggttagctcc ttcggtcctc
cgatcgttgt cagaagtaag ttggccgcag tgttatcact 2820catggttatg
gcagcactgc ataattctct tactgtcatg ccatccgtaa gatgcttttc
2880tgtgactggt gagtactcaa ccaagtcatt ctgagaatag tgtatgcggc
gaccgagttg 2940ctcttgcccg gcgtcaatac gggataatac cgcgccacat
agcagaactt taaaagtgct 3000catcattgga aaacgttctt cggggcgaaa
actctcaagg atcttaccgc tgttgagatc 3060cagttcgatg taacccactc
gtgcacccaa ctgatcttca gcatctttta ctttcaccag 3120cgtttctggg
tgagcaaaaa caggaaggca aaatgccgca aaaaagggaa taagggcgac
3180acggaaatgt tgaatactca tactcttcct ttttcaatat tattgaagca
tttatcaggg 3240ttattgtctc atgagcggat acatatttga atgtatttag
aaaaataaac aaataggggt 3300tccgcgcaca tttccccgaa aagtgccacc
tgacgtctaa gaaaccatta ttatcatgac 3360attaacctat aaaaataggc
gtatcacgag gccctttcgt ctcgcgcgtt tcggtgatga 3420cggtgaaaac
ctctgacaca tgcagctccc ggagacggtc acagcttgtc tgtaagcgga
3480tgccgggagc agacaagccc gtcagggcgc gtcagcgggt gttggcgggt
gtcggggctg 3540gcttaactat gcggcatcag agcagattgt actgagagtg
caccatatgc ggtgtgaaat 3600accgcacaga tgcgtaagga gaaaataccg
catcaggcgc cattcgccat tcaggctgcg 3660caactgttgg gaagggcgat
cggtgcgggc ctcttcgcta ttacgccagc tggcgaaagg 3720gggatgtgct
gcaaggcgat taagttgggt aacgccaggg ttttcccagt cacgacgttg
3780taaaacgacg gccagt 37963322DNAPorcine reproductive and
respiratory syndrome virus 33cgttaattaa accgactagt gc
223430DNAPorcine reproductive and respiratory syndrome virus
34tcgagcaatt aatttggctg atcacgccgg 303524DNAPorcine reproductive
and respiratory syndrome virus 35cggggacggt ttcaaatttc actt
243650DNAPorcine reproductive and respiratory syndrome virus
36tatataagca gagctcgtta attaaaccgt catgacgtat aggtgttggc
503748DNAPorcine reproductive and respiratory syndrome virus
37aggtcgacgg cggcaattgg tttcacctag agtggctgcg tcccttct
483830DNAPorcine reproductive and respiratory syndrome virus
38tcttaagcat tggctgtgat ggtgatatac 303944DNAPorcine reproductive
and respiratory syndrome virus 39cttcttaagt ccacgcgttt tcttcttgcc
ttttctatgc ttct 444019DNAPorcine reproductive and respiratory
syndrome virus 40tgcccggtcc cttgcctct 194126DNAPorcine reproductive
and respiratory syndrome virus 41gtttacgcgt cgctccttgg tggtcg
264223DNAPorcine reproductive and respiratory syndrome virus
42aacagaagag ttgtcgggtc cac 234349DNAPorcine reproductive and
respiratory syndrome virus 43gctttgacgc gtccccactt aagttcaatt
caggcctaaa gttggttca 494482DNAPorcine reproductive and respiratory
syndrome virus 44gcgacgcgtg ttccgtggca acccctttaa ccagagtttc
agcggaacaa tgaaatgggg 60tctatacaaa gcctcttcga ca 824526DNAPorcine
reproductive and respiratory syndrome virus 45aacagaacgg cacgatacac
cacaaa 264624DNAPorcine reproductive and respiratory syndrome virus
46caaagggcga aaaaccgtct atca 244723DNAPorcine reproductive and
respiratory syndrome virus 47ccccacttaa gttcaattca ggc
234837DNAPorcine reproductive and respiratory syndrome virus
48gctccttaag aacaacgcgt cgccattgaa gccgaga 374924DNAPorcine
reproductive and respiratory syndrome virus 49gcaagcctaa taacgaagca
aatc 245042DNAPorcine reproductive and respiratory syndrome virus
50ctgtcaagtg ttaggatcac gcgtccaaaa tactcagctc aa 425142DNAPorcine
reproductive and respiratory syndrome virus 51ttgagctgag tattttggac
gcgtgatcct aacacttgac ag 425233DNAPorcine reproductive and
respiratory syndrome virus 52gccacgcgtg ccaccatggt gagcaagggc gag
335331DNAPorcine reproductive and respiratory syndrome virus
53gccacgcgtg ttatctagat ccggtggatc c 315440DNAPorcine reproductive
and respiratory syndrome virus 54tcaagccgct ggcggctagc agtttaaaca
ctgctcctta 405541DNAPorcine reproductive and respiratory syndrome
virus 55ctcgggaaaa tagaaaacac cggtgagatg atcaaccagg g
415641DNAPorcine reproductive and respiratory syndrome virus
56ccctggttga tcatctcacc ggtgttttct attttcccga g 415740DNAPorcine
reproductive and respiratory syndrome virus 57gccgcccacc ggtgaggtga
gcaagggcga ggagctgttc 405837DNAPorcine reproductive and respiratory
syndrome virus 58gccgcccacc ggtgttgtta tctagatccg gtggatc
375930DNAPorcine reproductive and respiratory syndrome virus
59gccacgcgtg tgagcaaggg cgaggagctg 306033DNAPorcine reproductive
and respiratory syndrome virus 60cgcgtatacc catacgacgt cccagactac
gca 336133DNAPorcine reproductive and respiratory syndrome virus
61ccggtgcgta gtctgggacg tcgtatgggt ata 336239DNAPorcine
reproductive and respiratory syndrome virus 62ccctgtcaag tgttaagatc
acaggtgaga tgatcaacc 396341DNAPorcine reproductive and respiratory
syndrome virus 63ccctggttga tcatctcacc tgtgatctta acacttgaca g
4164132PRTPorcine reproductive and respiratory syndrome virus 64Arg
Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asp Leu Gly Gly Pro Cys1 5 10
15Ser Gly His Leu Gln Arg Glu Lys Glu Ala Cys Leu Arg Ile Met Arg
20 25 30Glu Ala Cys Asp Ala Ala Lys Leu Ser Asp Pro Ala Thr Gln Glu
Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg
Asn Thr 50 55 60Ser Ala Tyr Gln Ala Phe Arg Thr Leu Asp Gly Arg Phe
Gly Phe Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro Tyr
Pro Cys Gly Phe Val 85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val
Ser Ala Glu Ser Asp Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu
Asp Ile Pro Arg Ile Leu Gly Lys 115 120 125Ile Glu Asn Thr
13065132PRTPorcine reproductive and respiratory syndrome virus
65Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1
5 10 15Ser Gly His Leu Gln Glu Val Lys Glu Thr Cys Leu Ser Val Met
Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys Leu Asp Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp
Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala Ile Cys Thr Leu Asp Gly Arg
Leu Lys Phe Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro
Tyr Pro Cys Glu Phe Val 85 90 95Met Met Pro His Thr Pro Ala Pro Ser
Val Gly Ala Glu Ser Asp Leu 100 105 110Thr Ile Gly Ser Val Ala Thr
Glu Asp Val Pro Arg Ile Leu Glu Lys 115 120 125Ile Glu Asn Val
13066132PRTPorcine reproductive and respiratory syndrome virus
66Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1
5 10 15Ser Gly His Leu Gln Lys Glu Lys Glu Ala Cys Leu Ser Ile Met
Arg 20 25 30Glu Ala Cys Asp Ala Ser Lys Leu Ser Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp
Arg Asn Thr 50 55 60Ser Ala Tyr Gln Ala Phe Arg Thr Leu Asn Gly Arg
Phe Glu Phe Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro
His Pro Cys Gly Phe Val 85 90 95Met Leu Pro His Thr Pro Ala Pro Ser
Val Ser Ala Glu Ser Asp Leu 100 105 110Thr Ile Gly Ser Val Ala Thr
Glu Asp Val Pro Arg Ile Leu Gly Lys 115 120 125Ile Gly Asp Thr
13067132PRTPorcine reproductive and respiratory syndrome virus
67Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1
5 10 15Ser Gly His Leu Gln Lys Glu Lys Glu Ala Cys Leu Ser Ile Met
Arg 20 25 30Glu Ala Cys Asp Ala Ser Lys Leu Ser Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp
Arg Asn Thr 50 55 60Ser Ala Tyr Gln Ala Phe Arg Thr Leu Asn Gly Arg
Phe Glu Phe Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro
His Pro Cys Gly Phe Val 85 90 95Met Leu Pro His Thr Pro Ala Pro Ser
Val Ser Ala Glu Ser Asp Leu 100
105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Gly
Lys 115 120 125Ile Gly Asp Thr 13068132PRTPorcine reproductive and
respiratory syndrome virus 68Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Ala Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13069132PRTPorcine reproductive and
respiratory syndrome virus 69Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Ala Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Met Glu Asn Val 13070132PRTPorcine reproductive and
respiratory syndrome virus 70Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13071132PRTPorcine reproductive and
respiratory syndrome virus 71Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13072132PRTPorcine reproductive and
respiratory syndrome virus 72Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13073132PRTPorcine reproductive and
respiratory syndrome virus 73Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13074132PRTPorcine reproductive and
respiratory syndrome virus 74Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13075132PRTPorcine reproductive and
respiratory syndrome virus 75Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13076132PRTPorcine reproductive and
respiratory syndrome virus 76Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13077132PRTPorcine reproductive and
respiratory syndrome virus 77Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13078132PRTPorcine reproductive and
respiratory syndrome virus 78Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13079132PRTPorcine reproductive and
respiratory syndrome virus 79Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13080132PRTPorcine reproductive and
respiratory syndrome virus 80Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Gly Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Cys Gln Ala
Ile Arg Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13081132PRTPorcine reproductive and
respiratory syndrome virus 81Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Gly Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Cys Gln Ala
Ile Arg Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13082132PRTPorcine reproductive and
respiratory syndrome virus 82Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asn Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13083132PRTPorcine reproductive and
respiratory syndrome virus 83Arg Pro Thr Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Ala
Ile Cys Thr Leu Asp Gly Arg Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Glu Asn Val 13084132PRTPorcine reproductive and
respiratory syndrome virus 84Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Val Met Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val Tyr Gln Val
Ile Cys Thr Leu Asp Gly Met Leu Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Glu Phe Val 85 90 95Met Met
Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105
110Thr Ile Gly Ser Val Thr Thr Glu Asp Val Pro Arg Ile Leu Glu Lys
115 120 125Ile Gly Asn Val 13085132PRTPorcine reproductive and
respiratory syndrome virus 85Arg Pro Lys Tyr Ser Ala Gln Ala Ile
Ile Asp Ser Gly Gly Pro Tyr1 5 10 15Ser Gly His Leu Gln Glu Val Lys
Glu Thr Cys Leu Ser Ile Met Ser 20 25 30Glu Ala Cys Asp Val Thr Lys
Leu Asp Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp
Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser Val His Gln Ala
Ser Arg Thr Leu Asp Asp Arg Phe Lys Phe Leu65 70 75 80Pro Lys Met
Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Gly Phe Val 85 90 95Met Met
Pro Arg Thr Pro
Ala Pro Ser Val Gly Ala Glu Ser Asp Leu 100 105 110Thr Ile Gly Ser
Val Ala Thr Glu Asp Val Pro Arg Ile Phe Gly Lys 115 120 125Val Asn
Asp Val 13086132PRTPorcine reproductive and respiratory syndrome
virus 86Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro
Tyr1 5 10 15Ser Gly His Leu Gln Glu Val Lys Glu Thr Cys Leu Ser Ile
Met Ser 20 25 30Glu Ala Cys Asp Val Thr Lys Leu Asp Asp Pro Ala Thr
Gln Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr
Trp Arg Asn Thr 50 55 60Ser Val His Gln Ala Ser Arg Thr Leu Asp Asp
Arg Phe Lys Phe Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro
Pro Tyr Pro Cys Gly Phe Val 85 90 95Met Met Pro Arg Thr Pro Ala Pro
Ser Val Gly Ala Glu Ser Asp Leu 100 105 110Thr Ile Gly Ser Val Ala
Thr Glu Asp Val Pro Arg Ile Phe Gly Lys 115 120 125Val Asn Asp Val
13087132PRTPorcine reproductive and respiratory syndrome virus
87Arg Pro Lys His Ser Ala Gln Ala Ile Ile Asp Leu Val Gly Pro Cys1
5 10 15Ser Gly His Leu Gln Glu Val Lys Glu Ile Cys Leu Ser Val Met
Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys Leu Asn Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp
Arg Asn Thr 50 55 60Ser Ala Tyr Gln Thr Leu Ser Thr Leu Asp Gly Trp
Ser Arg Phe Leu65 70 75 80Pro Lys Leu Ile Leu Glu Thr Pro Pro Pro
Tyr Pro Cys Glu Phe Val 85 90 95Met Met Pro Tyr Thr Pro Ala Pro Ser
Val Gly Ala Glu Ser Asp Leu 100 105 110Thr Ile Gly Ser Val Ala Thr
Glu Asp Val Pro Arg Ile Leu Glu Asn 115 120 125Met Glu Asn Val
13088131PRTPorcine reproductive and respiratory syndrome virus
88Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1
5 10 15Ser Gly His Leu Gln Glu Val Lys Glu Thr Cys Leu Ser Val Met
Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys Leu Asp Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Cys
Asn Thr Ser 50 55 60Val Tyr Gln Ala Ile Cys Thr Leu Asp Gly Arg Leu
Lys Phe Leu Pro65 70 75 80Lys Leu Ile Leu Glu Thr Pro Pro Pro Tyr
Pro Cys Glu Phe Val Met 85 90 95Met Pro His Thr Pro Ala Pro Ser Val
Gly Ala Glu Ser Asp Leu Thr 100 105 110Ile Gly Ser Val Ala Thr Glu
Asp Val Pro Arg Ile Leu Glu Lys Thr 115 120 125Glu Asn Val
13089132PRTPorcine reproductive and respiratory syndrome virus
89Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asn Ser Gly Gly Pro Cys1
5 10 15Cys Gly His Leu Gln Glu Val Lys Glu Lys Tyr Leu Asn Val Met
Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys Leu Asp Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp
Arg Asn Thr 50 55 60Ser Ile Phe Gln Ala Pro Phe Thr Leu Ala Asp Lys
Phe Lys Ser Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro
Tyr Pro Cys Gly Phe Val 85 90 95Met Met Pro Arg Thr Pro Ala Pro Ser
Val Gly Ala Glu Ser Asp Leu 100 105 110Thr Val Gly Ser Val Ala Thr
Glu Asp Val Pro Arg Ile Leu Gly Lys 115 120 125Val Gln Gly Val
13090132PRTPorcine reproductive and respiratory syndrome virus
90Arg Pro Lys Tyr Ser Ala Gln Ala Ile Ile Asn Ser Gly Gly Pro Cys1
5 10 15Cys Gly His Leu Gln Glu Val Lys Glu Lys Tyr Leu Asn Val Met
Arg 20 25 30Glu Ala Cys Asp Ala Thr Lys Leu Asp Asp Pro Ala Thr Gln
Glu Trp 35 40 45Leu Ser Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp
Arg Asn Thr 50 55 60Ser Ile Phe Gln Ala Pro Phe Thr Leu Ala Asp Lys
Phe Lys Thr Leu65 70 75 80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro
Tyr Pro Cys Gly Phe Val 85 90 95Met Met Pro Arg Thr Pro Ala Pro Ser
Val Gly Ala Glu Ser Asp Leu 100 105 110Thr Val Gly Ser Val Ala Thr
Glu Asp Val Pro Arg Ile Leu Gly Asn 115 120 125Val Gln Gly Val
13091132PRTPorcine reproductive and respiratory syndrome virus
91Arg Pro Arg Tyr Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Ala Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Lys Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Arg Trp Asp Lys Lys 100 105 110Leu Ser Val Thr Pro Pro Leu
Lys Ser Ala Gly Leu Ala Leu Asp Gln 115 120 125Thr Val Pro Pro
13092132PRTPorcine reproductive and respiratory syndrome virus
92Arg Pro Arg Tyr Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Arg Gln Leu
Val Ala Arg Trp Asp Lys Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Ser Thr Gly Leu Val Leu Asp Gln 115 120 125Thr Val Pro Leu
13093132PRTPorcine reproductive and respiratory syndrome virus
93Arg Pro Arg Tyr Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Lys Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Arg Trp Asp Lys Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Ser Ala Gly Leu Val Leu Asn Gln 115 120 125Thr Val Pro Pro
13094132PRTPorcine reproductive and respiratory syndrome virus
94Arg Pro Arg Tyr Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Arg Gln Leu
Val Ala Arg Trp Asp Lys Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Ser Ala Gly Leu Val Leu Asp Gln 115 120 125Thr Val Pro Pro
13095132PRTPorcine reproductive and respiratory syndrome virus
95Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Pro Val Gly Pro Val Leu Asp Gln 115 120 125Ile Val Pro Pro
13096132PRTPorcine reproductive and respiratory syndrome virus
96Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Pro Val Gly Pro Val Leu Asp Gln 115 120 125Ile Val Pro Pro
13097132PRTPorcine reproductive and respiratory syndrome virus
97Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Ser Thr Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Leu Ser Val Ala Pro Pro Gln
Lys Pro Val Gly Pro Val Arg Asn Gln 115 120 125Ala Val Pro Pro
13098132PRTPorcine reproductive and respiratory syndrome virus
98Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Pro Val Gly Pro Val Leu Asp Gln 115 120 125Ile Val Pro Pro
13099132PRTPorcine reproductive and respiratory syndrome virus
99Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Pro Val Gly Pro Val Leu Asp Gln 115 120 125Thr Val Pro Pro
130100132PRTPorcine reproductive and respiratory syndrome virus
100Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Lys Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Phe Ser Val Thr Pro Pro Pro
Lys Leu Ala Gly Pro Val Leu Asp Gln 115 120 125Thr Val Leu Pro
130101132PRTPorcine reproductive and respiratory syndrome virus
101Arg Pro Arg His Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys Asn Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg
Glu Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Arg Trp Asp Lys Lys 100 105 110Leu Ser Val Thr Pro Pro Pro
Lys Ser Ala Gly Leu Val Leu Asp Gln 115 120 125Thr Val Pro Pro
130102132PRTPorcine reproductive and respiratory syndrome virus
102Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys His Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Lys Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu
Val Ala Gln Trp Asp Arg Lys 100 105 110Leu Ser Gly Thr Pro Pro Pro
Lys Ser Ala Gly Leu Val Leu Asp Gln 115 120 125Thr Val Pro Pro
130103132PRTPorcine reproductive and respiratory syndrome virus
103Arg Pro Arg Phe Ser Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1
5 10 15Ala Asp Val His Ala Lys Ile Lys His Arg Val Tyr Glu Gln Cys
Leu 20 25 30Gln Ala Cys Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys
Lys Trp 35 40 45Leu Asp Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp
Arg Cys Thr 50 55 60Ser Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu
Lys Phe Leu Pro65 70 75 80Asp Met Ile Gln Asp Thr Pro Pro Pro Val
Pro Arg Lys Asn
Arg Ala 85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu Val Ala Gln Trp
Asp Arg Lys 100 105 110Leu Ser Gly Thr Pro Pro Pro Lys Pro Ala Gly
Ser Val Leu Asp Gln 115 120 125Thr Val Pro Pro 130104132PRTPorcine
reproductive and respiratory syndrome virus 104Arg Pro Arg Phe Ser
Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1 5 10 15Ala Asp Val His
Ala Lys Ile Lys His Arg Val Tyr Glu Gln Cys Leu 20 25 30Gln Ala Cys
Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys Lys Trp 35 40 45Leu Asp
Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp Arg Cys Thr 50 55 60Ser
Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu Lys Phe Leu Pro65 70 75
80Asp Met Ile Gln Asp Thr Pro Pro Pro Val Pro Arg Lys Asn Arg Ala
85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu Val Ala Gln Trp Asp Arg
Lys 100 105 110Leu Ser Gly Thr Pro Pro Pro Lys Pro Ala Gly Ser Val
Leu Asp Gln 115 120 125Thr Val Pro Pro 130105132PRTPorcine
reproductive and respiratory syndrome virus 105Arg Pro Arg Phe Ser
Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1 5 10 15Ala Asp Val His
Ala Lys Ile Lys His Arg Val Tyr Glu Gln Cys Leu 20 25 30Gln Ala Cys
Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys Lys Trp 35 40 45Leu Asp
Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp Arg Cys Thr 50 55 60Ser
Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu Lys Phe Leu Pro65 70 75
80Asp Met Ile Gln Asp Thr Pro Pro Pro Val Pro Arg Lys Asn Arg Ala
85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu Val Ala Gln Trp Asp Arg
Lys 100 105 110Leu Ser Gly Thr Pro Pro Pro Lys Pro Ala Gly Ser Val
Phe Asp Gln 115 120 125Ala Val Pro Pro 130106132PRTPorcine
reproductive and respiratory syndrome virus 106Arg Pro Arg Phe Ser
Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1 5 10 15Ala Asp Val His
Ala Lys Ile Lys His Arg Val Tyr Glu Gln Cys Leu 20 25 30Gln Ala Cys
Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys Lys Trp 35 40 45Leu Asp
Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp Arg Cys Thr 50 55 60Ser
Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu Lys Phe Leu Pro65 70 75
80Asp Met Ile Gln Asp Thr Pro Pro Pro Val Pro Arg Lys Asn Arg Ala
85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu Val Ala Gln Trp Asp Arg
Lys 100 105 110Leu Ser Gly Thr Pro Pro Pro Lys Pro Ala Gly Ser Val
Leu Asp Gln 115 120 125Ala Val Pro Pro 130107132PRTPorcine
reproductive and respiratory syndrome virus 107Arg Pro Arg Phe Ser
Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1 5 10 15Ala Asp Val His
Ala Lys Ile Lys Asn Gln Val Tyr Glu Arg Cys Leu 20 25 30Gln Ala Cys
Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Arg Glu Trp 35 40 45Leu Asp
Lys Met Trp Glu Arg Val Asp Met Lys Thr Trp Arg Cys Thr 50 55 60Ser
Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu Lys Phe Leu Pro65 70 75
80Asp Met Ile Gln Asp Thr Pro Pro Pro Val Pro Arg Lys Asn Arg Ala
85 90 95Ser Asp Asn Ala Gly Leu Lys Gln Leu Val Ala Gln Trp Asp Arg
Lys 100 105 110Leu Ser Met Thr Ser Pro Gln Lys Pro Val Gly Ser Val
Leu Asp Gln 115 120 125Thr Ala Phe Pro 130108132PRTPorcine
reproductive and respiratory syndrome virus 108Arg Pro Arg Phe Ser
Ala Gln Ala Leu Ile Asp Arg Gly Gly Pro Leu1 5 10 15Ala Asp Val His
Ala Lys Ile Lys Asn Arg Val Tyr Glu Arg Cys Leu 20 25 30Gln Ala Cys
Glu Pro Gly Ser Arg Ala Thr Pro Ala Thr Lys Glu Trp 35 40 45Leu Asp
Lys Met Trp Asp Arg Val Asp Met Lys Thr Trp Cys Cys Thr 50 55 60Ser
Gln Phe Gln Ala Gly Arg Ile Leu Ala Ser Leu Lys Phe Leu Pro65 70 75
80Asp Met Ile Gln Asp Thr Pro Pro Pro Val Pro Arg Lys Asn Arg Ala
85 90 95Ser Asp Asn Ala Asp Leu Lys Gln Leu Val Ala Gln Trp Asp Arg
Lys 100 105 110Leu Ser Met Thr Pro Pro Gln Lys Pro Val Glu Pro Val
Leu Asp Gln 115 120 125Thr Val Ser Pro 130109132PRTPorcine
reproductive and respiratory syndrome virus 109Arg Pro Lys Tyr Ser
Ala Gln Ala Ile Ile Asp Leu Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Gln Arg Glu Lys Glu Ala Cys Leu Arg Ile Met Arg 20 25 30Glu Ala Cys
Asp Ala Ala Lys Leu Ser Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser
Ala Tyr Gln Ala Phe Arg Thr Leu Asp Gly Arg Phe Gly Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val Ser Ala Glu Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Ile Pro Arg Ile
Leu Gly Lys 115 120 125Ile Glu Asn Thr 130110132PRTPorcine
reproductive and respiratory syndrome virus 110Arg Pro Lys Tyr Ser
Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Gln Lys Glu Lys Glu Ala Cys Leu Arg Ile Met Arg 20 25 30Glu Ala Cys
Asp Ala Ala Arg Leu Gly Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
His Met Trp Asp Arg Val Asp Val Leu Thr Trp Arg Asn Thr 50 55 60Ser
Val Tyr Gln Ala Phe Arg Thr Leu Asp Gly Arg Phe Gly Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Thr Pro Ser Val Ser Ala Glu Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile
Leu Gly Lys 115 120 125Thr Glu Asn Thr 130111132PRTPorcine
reproductive and respiratory syndrome virus 111Arg Pro Lys Tyr Ser
Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Gln Arg Glu Lys Glu Ala Cys Leu Ser Ile Met Arg 20 25 30Glu Ala Cys
Asp Ala Ala Lys Leu Ser Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser
Ala Tyr Gln Ala Leu His Thr Leu Asp Gly Arg Ser Gly Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro His Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val Ser Ala Lys Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile
Leu Gly Lys 115 120 125Ile Glu Asn Thr 130112132PRTPorcine
reproductive and respiratory syndrome virus 112Arg Pro Lys Tyr Ser
Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Arg Arg Glu Lys Glu Ala Cys Leu Ser Ile Met Arg 20 25 30Lys Ala Cys
Asp Ala Ala Lys Leu Ser Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser
Ala Tyr Gln Ala Leu Arg Val Leu Asp Gly Arg Phe Gly Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val Ser Ala Glu Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile
Leu Gly Lys 115 120 125Thr Glu Asn Ala 130113132PRTPorcine
reproductive and respiratory syndrome virus 113Arg Pro Lys His Ser
Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Arg Arg Glu Lys Glu Ala Cys Leu Ser Ile Met Arg 20 25 30Glu Ala Cys
Asp Ala Ala Lys Leu Ser Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser
Ala Tyr Gln Ala Phe Arg Ile Leu Asp Gly Arg Phe Glu Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile
Leu Gly Lys 115 120 125Ile Glu Asn Ala 130114132PRTPorcine
reproductive and respiratory syndrome virus 114Arg Pro Lys His Ser
Ala Gln Ala Ile Ile Asp Ser Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Arg Arg Glu Lys Glu Ala Cys Leu Ser Ile Met Arg 20 25 30Glu Ala Cys
Asp Ala Ala Lys Leu Ser Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser
Ala Tyr Gln Ala Phe Arg Ile Leu Asp Gly Arg Phe Glu Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro Tyr Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val Gly Ala Glu Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile
Leu Gly Lys 115 120 125Ile Glu Asn Ala 130115132PRTPorcine
reproductive and respiratory syndrome virus 115Arg Pro Lys Tyr Ser
Ala Gln Ala Ile Ile Asp Phe Gly Gly Pro Cys1 5 10 15Ser Gly His Leu
Gln Lys Glu Lys Glu Ala Cys Leu Ser Ile Met Arg 20 25 30Glu Ala Cys
Asp Ala Ser Lys Leu Ser Asp Pro Ala Thr Gln Glu Trp 35 40 45Leu Ser
Arg Met Trp Asp Arg Val Asp Met Leu Thr Trp Arg Asn Thr 50 55 60Ser
Ala Tyr Gln Ala Phe Arg Thr Leu Asn Gly Arg Phe Glu Phe Leu65 70 75
80Pro Lys Met Ile Leu Glu Thr Pro Pro Pro His Pro Cys Gly Phe Val
85 90 95Met Leu Pro His Thr Pro Ala Pro Ser Val Ser Ala Glu Ser Asp
Leu 100 105 110Thr Ile Gly Ser Val Ala Thr Glu Asp Val Pro Arg Ile
Leu Gly Lys 115 120 125Ile Gly Asp Thr 130
* * * * *